From 8cc61e1d4b28fd6bbfeabbaadb51f066e0b92bb4 Mon Sep 17 00:00:00 2001
From: Dorel Luca <dluca@mozilla.com>
Date: Sat, 18 Jan 2020 15:39:55 +0200
Subject: [PATCH] Backed out changeset bbb39655cf71 (bug 1605934) for build
 bustage in widget/gtk/mozwayland/mozwayland.c

---
 dom/base/nsFrameMessageManager.cpp            |  6 ++--
 dom/base/nsTextFragmentSSE2.cpp               |  6 ++--
 dom/battery/BatteryManager.cpp                |  8 ++++--
 dom/canvas/ImageUtils.cpp                     |  6 ++--
 dom/geolocation/GeolocationCoordinates.cpp    |  6 ++--
 dom/geolocation/GeolocationPosition.cpp       |  6 ++--
 dom/geolocation/GeolocationPositionError.cpp  |  6 ++--
 dom/html/PluginDocument.cpp                   |  6 ++--
 dom/indexedDB/ActorsParent.cpp                |  6 ++--
 dom/indexedDB/Key.cpp                         |  8 ++++--
 dom/plugins/base/nsNPAPIPlugin.cpp            |  8 ++++--
 dom/plugins/base/nsPluginHost.cpp             |  6 ++--
 .../PrototypeDocumentContentSink.cpp          |  6 ++--
 gfx/2d/BlurSSE2.cpp                           |  6 ++--
 gfx/2d/ConvolutionFilter.cpp                  |  6 ++--
 gfx/2d/DrawTargetSkia.cpp                     |  6 ++--
 gfx/2d/Factory.cpp                            |  6 ++--
 gfx/2d/FilterProcessingSSE2.cpp               |  6 ++--
 gfx/2d/ImageScalingSSE2.cpp                   |  6 ++--
 gfx/2d/InlineTranslator.cpp                   |  6 ++--
 gfx/2d/JobScheduler_posix.cpp                 |  6 ++--
 gfx/2d/NativeFontResourceFreeType.cpp         |  6 ++--
 gfx/2d/PathSkia.cpp                           |  6 ++--
 gfx/2d/ScaledFontFontconfig.cpp               |  6 ++--
 gfx/2d/SourceSurfaceSkia.cpp                  |  6 ++--
 gfx/2d/SwizzleAVX2.cpp                        |  6 ++--
 gfx/2d/SwizzleSSE2.cpp                        |  6 ++--
 gfx/2d/SwizzleSSSE3.cpp                       |  6 ++--
 gfx/2d/UnscaledFontFreeType.cpp               |  6 ++--
 gfx/gl/GLContextProviderGLX.cpp               |  6 ++--
 gfx/gl/GLContextProviderWayland.cpp           |  6 ++--
 gfx/gl/GLScreenBuffer.cpp                     |  6 ++--
 gfx/gl/SharedSurfaceGLX.cpp                   |  6 ++--
 gfx/ipc/GPUParent.cpp                         |  6 ++--
 gfx/layers/ImageContainer.cpp                 |  6 ++--
 gfx/layers/basic/BasicImageLayer.cpp          |  6 ++--
 gfx/layers/basic/TextureClientX11.cpp         |  6 ++--
 gfx/layers/basic/X11TextureSourceBasic.cpp    |  6 ++--
 gfx/layers/client/TextureClient.cpp           |  6 ++--
 gfx/layers/composite/X11TextureHost.cpp       |  6 ++--
 .../opengl/WaylandDMABUFTextureClientOGL.cpp  |  6 ++--
 .../opengl/WaylandDMABUFTextureHostOGL.cpp    |  6 ++--
 gfx/layers/opengl/X11TextureSourceOGL.cpp     |  6 ++--
 gfx/layers/wr/WebRenderTextureHost.cpp        |  6 ++--
 gfx/thebes/PrintTarget.cpp                    |  6 ++--
 gfx/thebes/PrintTargetPDF.cpp                 |  6 ++--
 gfx/thebes/PrintTargetPS.cpp                  |  6 ++--
 gfx/thebes/PrintTargetSkPDF.cpp               |  6 ++--
 gfx/thebes/PrintTargetThebes.cpp              |  6 ++--
 gfx/vr/VRManager.cpp                          |  6 ++--
 gfx/vr/VRPuppetCommandBuffer.cpp              |  6 ++--
 gfx/vr/ipc/VRLayerChild.cpp                   |  6 ++--
 gfx/vr/service/OpenVRSession.cpp              |  6 ++--
 gfx/vr/service/PuppetSession.cpp              |  6 ++--
 .../RenderCompositorEGL.cpp                   |  8 ++++--
 .../RenderWaylandDMABUFTextureHostOGL.cpp     |  6 ++--
 hal/Hal.cpp                                   |  6 ++--
 ipc/glue/BackgroundChildImpl.cpp              |  6 ++--
 ipc/glue/BackgroundParentImpl.cpp             |  6 ++--
 ipc/glue/FileDescriptorSetChild.cpp           |  6 ++--
 ipc/glue/FileDescriptorSetParent.cpp          |  6 ++--
 js/ductwork/debugger/JSDebugger.cpp           |  6 ++--
 js/src/ctypes/CTypes.cpp                      |  6 ++--
 js/src/ctypes/Library.cpp                     |  6 ++--
 js/src/frontend/BinASTParser.cpp              |  6 ++--
 js/src/frontend/BinASTParserBase.cpp          |  6 ++--
 js/src/frontend/BinASTParserPerTokenizer.cpp  |  6 ++--
 js/src/frontend/BinASTRuntimeSupport.cpp      |  7 +++--
 js/src/frontend/BinASTTokenReaderBase.cpp     |  6 ++--
 js/src/frontend/BinASTTokenReaderContext.cpp  |  7 +++--
 .../frontend/BinASTTokenReaderMultipart.cpp   |  7 +++--
 js/src/frontend/Parser.cpp                    |  6 ++--
 js/src/vtune/VTuneWrapper.cpp                 |  6 ++--
 layout/ipc/VsyncChild.cpp                     |  6 ++--
 media/mtransport/WebrtcTCPSocketWrapper.cpp   |  6 ++--
 mfbt/RecordReplay.cpp                         |  6 ++--
 netwerk/base/NetworkInfoServiceLinux.cpp      |  6 ++--
 netwerk/base/nsNetworkInfoService.cpp         |  6 ++--
 netwerk/build/nsNetModule.cpp                 |  6 ++--
 netwerk/cache2/AppCacheStorage.cpp            |  6 ++--
 netwerk/cache2/CacheStorage.cpp               |  6 ++--
 netwerk/dns/nsHostResolver.cpp                |  6 ++--
 .../http/nsHttpChannelAuthProvider.cpp        |  6 ++--
 netwerk/protocol/http/nsHttpHandler.cpp       |  9 ++++--
 netwerk/system/netlink/NetlinkService.cpp     |  6 ++--
 storage/mozStorageBindingParams.cpp           |  6 ++--
 storage/mozStorageConnection.cpp              |  6 ++--
 toolkit/components/ctypes/ctypes.cpp          |  6 ++--
 toolkit/components/reflect/reflect.cpp        |  6 ++--
 .../components/telemetry/core/Stopwatch.cpp   |  6 ++--
 .../components/telemetry/core/Telemetry.cpp   | 12 ++++----
 .../telemetry/core/TelemetryCommon.cpp        |  8 ++++--
 .../telemetry/other/CombinedStacks.cpp        |  6 ++--
 .../telemetry/other/KeyedStackCapturer.cpp    |  6 ++--
 .../telemetry/other/ProcessedStack.cpp        |  6 ++--
 .../other/TelemetryIOInterposeObserver.cpp    |  6 ++--
 .../components/url-classifier/HashStore.cpp   |  6 ++--
 .../VariableLengthPrefixSet.cpp               |  6 ++--
 toolkit/xre/nsAppRunner.cpp                   |  6 ++--
 toolkit/xre/nsEmbedFunctions.cpp              |  6 ++--
 tools/profiler/core/memory_hooks.cpp          | 12 +++++---
 widget/GfxInfoX11.cpp                         |  6 ++--
 widget/LSBUtils.cpp                           |  8 ++++--
 widget/ScreenManager.cpp                      |  6 ++--
 widget/WindowSurfaceX11SHM.cpp                |  6 ++--
 widget/gtk/MediaKeysEventSourceFactory.cpp    |  6 ++--
 widget/gtk/mozwayland/mozwayland.c            | 28 +++++++++----------
 widget/nsBaseWidget.cpp                       | 12 +++++---
 108 files changed, 469 insertions(+), 237 deletions(-)

diff --git a/dom/base/nsFrameMessageManager.cpp b/dom/base/nsFrameMessageManager.cpp
index 26410f80585d..14e118b2370d 100644
--- a/dom/base/nsFrameMessageManager.cpp
+++ b/dom/base/nsFrameMessageManager.cpp
@@ -990,7 +990,8 @@ struct MessageManagerReferentCount {
 
 }  // namespace
 
-namespace mozilla::dom {
+namespace mozilla {
+namespace dom {
 
 class MessageManagerReporter final : public nsIMemoryReporter {
   ~MessageManagerReporter() = default;
@@ -1124,7 +1125,8 @@ MessageManagerReporter::CollectReports(nsIHandleReportCallback* aHandleReport,
   return NS_OK;
 }
 
-}  // namespace mozilla::dom
+}  // namespace dom
+}  // namespace mozilla
 
 already_AddRefed<ChromeMessageBroadcaster>
 nsFrameMessageManager::GetGlobalMessageManager() {
diff --git a/dom/base/nsTextFragmentSSE2.cpp b/dom/base/nsTextFragmentSSE2.cpp
index 48dcbdb9fce0..b6f5817cc32a 100644
--- a/dom/base/nsTextFragmentSSE2.cpp
+++ b/dom/base/nsTextFragmentSSE2.cpp
@@ -13,7 +13,8 @@
 #include "nsTextFragmentImpl.h"
 #include <algorithm>
 
-namespace mozilla::SSE2 {
+namespace mozilla {
+namespace SSE2 {
 
 static inline bool is_zero(__m128i x) {
   return _mm_movemask_epi8(_mm_cmpeq_epi8(x, _mm_setzero_si128())) == 0xffff;
@@ -63,4 +64,5 @@ int32_t FirstNon8Bit(const char16_t* str, const char16_t* end) {
   return -1;
 }
 
-}  // namespace mozilla::SSE2
+}  // namespace SSE2
+}  // namespace mozilla
diff --git a/dom/battery/BatteryManager.cpp b/dom/battery/BatteryManager.cpp
index a536ee9fd1da..04fcb25eae47 100644
--- a/dom/battery/BatteryManager.cpp
+++ b/dom/battery/BatteryManager.cpp
@@ -25,7 +25,9 @@
   NS_LITERAL_STRING("dischargingtimechange")
 #define CHARGINGTIMECHANGE_EVENT_NAME NS_LITERAL_STRING("chargingtimechange")
 
-namespace mozilla::dom::battery {
+namespace mozilla {
+namespace dom {
+namespace battery {
 
 BatteryManager::BatteryManager(nsPIDOMWindowInner* aWindow)
     : DOMEventTargetHelper(aWindow),
@@ -181,4 +183,6 @@ void BatteryManager::Notify(const hal::BatteryInformation& aBatteryInfo) {
   }
 }
 
-}  // namespace mozilla::dom::battery
+}  // namespace battery
+}  // namespace dom
+}  // namespace mozilla
diff --git a/dom/canvas/ImageUtils.cpp b/dom/canvas/ImageUtils.cpp
index de946c656030..ded585c019ba 100644
--- a/dom/canvas/ImageUtils.cpp
+++ b/dom/canvas/ImageUtils.cpp
@@ -13,7 +13,8 @@
 using namespace mozilla::layers;
 using namespace mozilla::gfx;
 
-namespace mozilla::dom {
+namespace mozilla {
+namespace dom {
 
 static ImageBitmapFormat GetImageBitmapFormatFromSurfaceFromat(
     SurfaceFormat aSurfaceFormat) {
@@ -199,4 +200,5 @@ uint32_t ImageUtils::GetBufferLength() const {
   return mImpl->GetBufferLength();
 }
 
-}  // namespace mozilla::dom
+}  // namespace dom
+}  // namespace mozilla
diff --git a/dom/geolocation/GeolocationCoordinates.cpp b/dom/geolocation/GeolocationCoordinates.cpp
index 3ec4d55b125a..5d17da374c00 100644
--- a/dom/geolocation/GeolocationCoordinates.cpp
+++ b/dom/geolocation/GeolocationCoordinates.cpp
@@ -10,7 +10,8 @@
 #include "mozilla/dom/GeolocationPositionBinding.h"
 #include "mozilla/dom/GeolocationCoordinatesBinding.h"
 
-namespace mozilla::dom {
+namespace mozilla {
+namespace dom {
 
 NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(GeolocationCoordinates, mPosition)
 NS_IMPL_CYCLE_COLLECTING_ADDREF(GeolocationCoordinates)
@@ -64,4 +65,5 @@ GENERATE_COORDS_WRAPPED_GETTER_NULLABLE(Speed)
 #undef GENERATE_COORDS_WRAPPED_GETTER
 #undef GENERATE_COORDS_WRAPPED_GETTER_NULLABLE
 
-}  // namespace mozilla::dom
+}  // namespace dom
+}  // namespace mozilla
diff --git a/dom/geolocation/GeolocationPosition.cpp b/dom/geolocation/GeolocationPosition.cpp
index bb113c4651d7..eb14e0b0775f 100644
--- a/dom/geolocation/GeolocationPosition.cpp
+++ b/dom/geolocation/GeolocationPosition.cpp
@@ -142,7 +142,8 @@ nsGeoPosition::GetCoords(nsIDOMGeoPositionCoords** aCoords) {
   return NS_OK;
 }
 
-namespace mozilla::dom {
+namespace mozilla {
+namespace dom {
 
 NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(GeolocationPosition, mParent,
                                       mCoordinates)
@@ -185,4 +186,5 @@ uint64_t GeolocationPosition::Timestamp() const {
   return rv;
 }
 
-}  // namespace mozilla::dom
+}  // namespace dom
+}  // namespace mozilla
diff --git a/dom/geolocation/GeolocationPositionError.cpp b/dom/geolocation/GeolocationPositionError.cpp
index efeaaddc05a7..2456b32dd119 100644
--- a/dom/geolocation/GeolocationPositionError.cpp
+++ b/dom/geolocation/GeolocationPositionError.cpp
@@ -9,7 +9,8 @@
 #include "mozilla/CycleCollectedJSContext.h"  // for nsAutoMicroTask
 #include "Geolocation.h"
 
-namespace mozilla::dom {
+namespace mozilla {
+namespace dom {
 
 NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(GeolocationPositionError, mParent)
 NS_IMPL_CYCLE_COLLECTION_ROOT_NATIVE(GeolocationPositionError, AddRef)
@@ -63,4 +64,5 @@ void GeolocationPositionError::NotifyCallback(
   }
 }
 
-}  // namespace mozilla::dom
+}  // namespace dom
+}  // namespace mozilla
diff --git a/dom/html/PluginDocument.cpp b/dom/html/PluginDocument.cpp
index 764215a9b8fb..c9ec51f96407 100644
--- a/dom/html/PluginDocument.cpp
+++ b/dom/html/PluginDocument.cpp
@@ -19,7 +19,8 @@
 #include "nsObjectLoadingContent.h"
 #include "GeckoProfiler.h"
 
-namespace mozilla::dom {
+namespace mozilla {
+namespace dom {
 
 class PluginDocument final : public MediaDocument, public nsIPluginDocument {
  public:
@@ -257,7 +258,8 @@ PluginDocument::Print() {
   return NS_OK;
 }
 
-}  // namespace mozilla::dom
+}  // namespace dom
+}  // namespace mozilla
 
 nsresult NS_NewPluginDocument(mozilla::dom::Document** aResult) {
   auto* doc = new mozilla::dom::PluginDocument();
diff --git a/dom/indexedDB/ActorsParent.cpp b/dom/indexedDB/ActorsParent.cpp
index 18136cea6071..e3a67e96c150 100644
--- a/dom/indexedDB/ActorsParent.cpp
+++ b/dom/indexedDB/ActorsParent.cpp
@@ -141,7 +141,8 @@ namespace mozilla {
 MOZ_TYPE_SPECIFIC_SCOPED_POINTER_TEMPLATE(ScopedPRFileDesc, PRFileDesc,
                                           PR_Close);
 
-namespace dom::indexedDB {
+namespace dom {
+namespace indexedDB {
 
 using namespace mozilla::dom::quota;
 using namespace mozilla::ipc;
@@ -27675,7 +27676,8 @@ nsresult FileHelper::SyncCopy(nsIInputStream* aInputStream,
   return rv;
 }
 
-}  // namespace dom::indexedDB
+}  // namespace indexedDB
+}  // namespace dom
 }  // namespace mozilla
 
 #undef IDB_MOBILE
diff --git a/dom/indexedDB/Key.cpp b/dom/indexedDB/Key.cpp
index f000a7b22c6a..ad05272772c4 100644
--- a/dom/indexedDB/Key.cpp
+++ b/dom/indexedDB/Key.cpp
@@ -27,7 +27,9 @@
 #include "unicode/ucol.h"
 #include "xpcpublic.h"
 
-namespace mozilla::dom::indexedDB {
+namespace mozilla {
+namespace dom {
+namespace indexedDB {
 
 /*
  Here's how we encode keys:
@@ -885,4 +887,6 @@ nsresult Key::SetFromSource(T* aSource, uint32_t aIndex) {
   return NS_OK;
 }
 
-}  // namespace mozilla::dom::indexedDB
+}  // namespace indexedDB
+}  // namespace dom
+}  // namespace mozilla
diff --git a/dom/plugins/base/nsNPAPIPlugin.cpp b/dom/plugins/base/nsNPAPIPlugin.cpp
index a3aba2a646cc..deeafcc99493 100644
--- a/dom/plugins/base/nsNPAPIPlugin.cpp
+++ b/dom/plugins/base/nsNPAPIPlugin.cpp
@@ -456,7 +456,9 @@ void PopException() {
 // Static callbacks that get routed back through the new C++ API
 //
 
-namespace mozilla::plugins::parent {
+namespace mozilla {
+namespace plugins {
+namespace parent {
 
 NPError _geturl(NPP npp, const char* relativeURL, const char* target) {
   if (!NS_IsMainThread()) {
@@ -1881,4 +1883,6 @@ void _setcurrentasyncsurface(NPP instance, NPAsyncSurface* surface,
   inst->SetCurrentAsyncSurface(surface, changed);
 }
 
-}  // namespace mozilla::plugins::parent
+} /* namespace parent */
+} /* namespace plugins */
+} /* namespace mozilla */
diff --git a/dom/plugins/base/nsPluginHost.cpp b/dom/plugins/base/nsPluginHost.cpp
index 93e50b4efac4..ec2442b68f3d 100644
--- a/dom/plugins/base/nsPluginHost.cpp
+++ b/dom/plugins/base/nsPluginHost.cpp
@@ -154,7 +154,8 @@ static bool IsTypeInList(const nsCString& aMimeType, nsCString aTypeList) {
   return FindInReadable(commaSeparated, start, end);
 }
 
-namespace mozilla::plugins {
+namespace mozilla {
+namespace plugins {
 class BlocklistPromiseHandler final
     : public mozilla::dom::PromiseNativeHandler {
  public:
@@ -259,7 +260,8 @@ NS_IMPL_ISUPPORTS0(BlocklistPromiseHandler)
 bool BlocklistPromiseHandler::sPluginBlocklistStatesChangedSinceLastWrite =
     false;
 uint32_t BlocklistPromiseHandler::sPendingBlocklistStateRequests = 0;
-}  // namespace mozilla::plugins
+}  // namespace plugins
+}  // namespace mozilla
 
 nsPluginHost::nsPluginHost()
     : mPluginsLoaded(false),
diff --git a/dom/prototype/PrototypeDocumentContentSink.cpp b/dom/prototype/PrototypeDocumentContentSink.cpp
index c5a9eecc0c82..ad686c19496e 100644
--- a/dom/prototype/PrototypeDocumentContentSink.cpp
+++ b/dom/prototype/PrototypeDocumentContentSink.cpp
@@ -77,7 +77,8 @@ nsresult NS_NewPrototypeDocumentContentSink(nsIContentSink** aResult,
   return NS_OK;
 }
 
-namespace mozilla::dom {
+namespace mozilla {
+namespace dom {
 
 PrototypeDocumentContentSink::PrototypeDocumentContentSink()
     : mNextSrcLoadWaiter(nullptr),
@@ -1079,4 +1080,5 @@ nsresult PrototypeDocumentContentSink::AddAttributes(
   return NS_OK;
 }
 
-}  // namespace mozilla::dom
+}  // namespace dom
+}  // namespace mozilla
diff --git a/gfx/2d/BlurSSE2.cpp b/gfx/2d/BlurSSE2.cpp
index 69a30367baca..5514e48e8ebe 100644
--- a/gfx/2d/BlurSSE2.cpp
+++ b/gfx/2d/BlurSSE2.cpp
@@ -10,7 +10,8 @@
 
 #include <string.h>
 
-namespace mozilla::gfx {
+namespace mozilla {
+namespace gfx {
 
 MOZ_ALWAYS_INLINE
 __m128i Divide(__m128i aValues, __m128i aDivisor) {
@@ -342,4 +343,5 @@ void AlphaBoxBlur::BoxBlur_SSE2(uint8_t* aData, int32_t aLeftLobe,
   }
 }
 
-}  // namespace mozilla::gfx
+}  // namespace gfx
+}  // namespace mozilla
diff --git a/gfx/2d/ConvolutionFilter.cpp b/gfx/2d/ConvolutionFilter.cpp
index 07498d0f5af9..938dcc560930 100644
--- a/gfx/2d/ConvolutionFilter.cpp
+++ b/gfx/2d/ConvolutionFilter.cpp
@@ -13,7 +13,8 @@
 #include <cmath>
 #include "mozilla/Vector.h"
 
-namespace mozilla::gfx {
+namespace mozilla {
+namespace gfx {
 
 ConvolutionFilter::ConvolutionFilter()
     : mFilter(MakeUnique<SkConvolutionFilter1D>()) {}
@@ -162,4 +163,5 @@ bool ConvolutionFilter::ComputeResizeFilter(ResizeMethod aResizeMethod,
   return mFilter->maxFilter() > 0 && mFilter->numValues() == aDstSize;
 }
 
-}  // namespace mozilla::gfx
+}  // namespace gfx
+}  // namespace mozilla
diff --git a/gfx/2d/DrawTargetSkia.cpp b/gfx/2d/DrawTargetSkia.cpp
index 563c55ad5714..e7aef2487bb0 100644
--- a/gfx/2d/DrawTargetSkia.cpp
+++ b/gfx/2d/DrawTargetSkia.cpp
@@ -42,7 +42,8 @@
 #  include "ScaledFontDWrite.h"
 #endif
 
-namespace mozilla::gfx {
+namespace mozilla {
+namespace gfx {
 
 class GradientStopsSkia : public GradientStops {
  public:
@@ -1884,4 +1885,5 @@ void DrawTargetSkia::MarkChanged() {
   }
 }
 
-}  // namespace mozilla::gfx
+}  // namespace gfx
+}  // namespace mozilla
diff --git a/gfx/2d/Factory.cpp b/gfx/2d/Factory.cpp
index f62d8bdee715..8f816bcde907 100644
--- a/gfx/2d/Factory.cpp
+++ b/gfx/2d/Factory.cpp
@@ -202,7 +202,8 @@ void mozilla_UnlockFTLibrary(FT_Library aFTLibrary) {
 }
 #endif
 
-namespace mozilla::gfx {
+namespace mozilla {
+namespace gfx {
 
 #ifdef MOZ_ENABLE_FREETYPE
 FT_Library Factory::mFTLibrary = nullptr;
@@ -1377,4 +1378,5 @@ void LogWStr(const wchar_t* aWStr, std::stringstream& aOut) {
 }
 #endif
 
-}  // namespace mozilla::gfx
+}  // namespace gfx
+}  // namespace mozilla
diff --git a/gfx/2d/FilterProcessingSSE2.cpp b/gfx/2d/FilterProcessingSSE2.cpp
index 0b9e0aa3d1f5..6dff63461331 100644
--- a/gfx/2d/FilterProcessingSSE2.cpp
+++ b/gfx/2d/FilterProcessingSSE2.cpp
@@ -13,7 +13,8 @@ static_assert(
     false, "If this file is built, FilterProcessing.h should know about it!");
 #endif
 
-namespace mozilla::gfx {
+namespace mozilla {
+namespace gfx {
 
 void FilterProcessing::ExtractAlpha_SSE2(const IntSize& size,
                                          uint8_t* sourceData,
@@ -123,4 +124,5 @@ FilterProcessing::ApplyArithmeticCombine_SSE2(DataSourceSurface* aInput1,
       aInput1, aInput2, aK1, aK2, aK3, aK4);
 }
 
-}  // namespace mozilla::gfx
+}  // namespace gfx
+}  // namespace mozilla
diff --git a/gfx/2d/ImageScalingSSE2.cpp b/gfx/2d/ImageScalingSSE2.cpp
index f901641eaf93..b43eb8183879 100644
--- a/gfx/2d/ImageScalingSSE2.cpp
+++ b/gfx/2d/ImageScalingSSE2.cpp
@@ -134,7 +134,8 @@ MOZ_ALWAYS_INLINE uint32_t Avg2(uint32_t a, uint32_t b) {
   return ((sum & mask) >> 1) + carry;
 }
 
-namespace mozilla::gfx {
+namespace mozilla {
+namespace gfx {
 
 void ImageHalfScaler::HalfImage2D_SSE2(uint8_t* aSource, int32_t aSourceStride,
                                        const IntSize& aSourceSize,
@@ -330,4 +331,5 @@ void ImageHalfScaler::HalfImageHorizontal_SSE2(uint8_t* aSource,
   }
 }
 
-}  // namespace mozilla::gfx
+}  // namespace gfx
+}  // namespace mozilla
diff --git a/gfx/2d/InlineTranslator.cpp b/gfx/2d/InlineTranslator.cpp
index 9ace1d8d31d1..eae23d9b48ba 100644
--- a/gfx/2d/InlineTranslator.cpp
+++ b/gfx/2d/InlineTranslator.cpp
@@ -15,7 +15,8 @@
 
 using namespace mozilla::gfx;
 
-namespace mozilla::gfx {
+namespace mozilla {
+namespace gfx {
 
 InlineTranslator::InlineTranslator() : mFontContext(nullptr) {}
 
@@ -109,4 +110,5 @@ already_AddRefed<DrawTarget> InlineTranslator::CreateDrawTarget(
   return drawTarget.forget();
 }
 
-}  // namespace mozilla::gfx
+}  // namespace gfx
+}  // namespace mozilla
diff --git a/gfx/2d/JobScheduler_posix.cpp b/gfx/2d/JobScheduler_posix.cpp
index 8287c8220cde..81f302b5f394 100644
--- a/gfx/2d/JobScheduler_posix.cpp
+++ b/gfx/2d/JobScheduler_posix.cpp
@@ -7,7 +7,8 @@
 #include "JobScheduler.h"
 #include "mozilla/gfx/Logging.h"
 
-namespace mozilla::gfx {
+namespace mozilla {
+namespace gfx {
 
 void* ThreadCallback(void* threadData);
 
@@ -152,4 +153,5 @@ void EventObject::Wait() {
   mCond.Wait(&mMutex);
 }
 
-}  // namespace mozilla::gfx
+}  // namespace gfx
+}  // namespace mozilla
diff --git a/gfx/2d/NativeFontResourceFreeType.cpp b/gfx/2d/NativeFontResourceFreeType.cpp
index 98e06a0e2beb..49234c0694ae 100644
--- a/gfx/2d/NativeFontResourceFreeType.cpp
+++ b/gfx/2d/NativeFontResourceFreeType.cpp
@@ -8,7 +8,8 @@
 #include "UnscaledFontFreeType.h"
 #include "Logging.h"
 
-namespace mozilla::gfx {
+namespace mozilla {
+namespace gfx {
 
 NativeFontResourceFreeType::NativeFontResourceFreeType(
     UniquePtr<uint8_t[]>&& aFontData, uint32_t aDataLength,
@@ -89,4 +90,5 @@ NativeFontResourceFontconfig::Create(uint8_t* aFontData, uint32_t aDataLength,
 }
 #endif
 
-}  // namespace mozilla::gfx
+}  // namespace gfx
+}  // namespace mozilla
diff --git a/gfx/2d/PathSkia.cpp b/gfx/2d/PathSkia.cpp
index 5c7895ac6b8b..ce405db9a054 100644
--- a/gfx/2d/PathSkia.cpp
+++ b/gfx/2d/PathSkia.cpp
@@ -11,7 +11,8 @@
 #include "HelpersSkia.h"
 #include "PathHelpers.h"
 
-namespace mozilla::gfx {
+namespace mozilla {
+namespace gfx {
 
 PathBuilderSkia::PathBuilderSkia(const Matrix& aTransform, const SkPath& aPath,
                                  FillRule aFillRule)
@@ -202,4 +203,5 @@ void PathSkia::StreamToSink(PathSink* aSink) const {
   }
 }
 
-}  // namespace mozilla::gfx
+}  // namespace gfx
+}  // namespace mozilla
diff --git a/gfx/2d/ScaledFontFontconfig.cpp b/gfx/2d/ScaledFontFontconfig.cpp
index c423966b8a2c..e62248c5f0a3 100644
--- a/gfx/2d/ScaledFontFontconfig.cpp
+++ b/gfx/2d/ScaledFontFontconfig.cpp
@@ -21,7 +21,8 @@
 #include FT_LCD_FILTER_H
 #include FT_MULTIPLE_MASTERS_H
 
-namespace mozilla::gfx {
+namespace mozilla {
+namespace gfx {
 
 ScaledFontFontconfig::ScaledFontFontconfig(
     RefPtr<SharedFTFace>&& aFace, FcPattern* aPattern,
@@ -520,4 +521,5 @@ already_AddRefed<UnscaledFont> UnscaledFontFontconfig::CreateFromFontDescriptor(
   return unscaledFont.forget();
 }
 
-}  // namespace mozilla::gfx
+}  // namespace gfx
+}  // namespace mozilla
diff --git a/gfx/2d/SourceSurfaceSkia.cpp b/gfx/2d/SourceSurfaceSkia.cpp
index cb685a92ef6b..d46ba1b0dfa1 100644
--- a/gfx/2d/SourceSurfaceSkia.cpp
+++ b/gfx/2d/SourceSurfaceSkia.cpp
@@ -12,7 +12,8 @@
 #include "skia/include/core/SkData.h"
 #include "mozilla/CheckedInt.h"
 
-namespace mozilla::gfx {
+namespace mozilla {
+namespace gfx {
 
 SourceSurfaceSkia::SourceSurfaceSkia()
     : mFormat(SurfaceFormat::UNKNOWN),
@@ -170,4 +171,5 @@ void SourceSurfaceSkia::DrawTargetWillChange() {
   }
 }
 
-}  // namespace mozilla::gfx
+}  // namespace gfx
+}  // namespace mozilla
diff --git a/gfx/2d/SwizzleAVX2.cpp b/gfx/2d/SwizzleAVX2.cpp
index fe8fbf453001..7c618e38785c 100644
--- a/gfx/2d/SwizzleAVX2.cpp
+++ b/gfx/2d/SwizzleAVX2.cpp
@@ -9,7 +9,8 @@
 #include <immintrin.h>
 #include <tmmintrin.h>
 
-namespace mozilla::gfx {
+namespace mozilla {
+namespace gfx {
 
 template <bool aSwapRB>
 void UnpackRowRGB24_SSSE3(const uint8_t* aSrc, uint8_t* aDst, int32_t aLength);
@@ -80,4 +81,5 @@ void UnpackRowRGB24_AVX2(const uint8_t* aSrc, uint8_t* aDst, int32_t aLength) {
 template void UnpackRowRGB24_AVX2<false>(const uint8_t*, uint8_t*, int32_t);
 template void UnpackRowRGB24_AVX2<true>(const uint8_t*, uint8_t*, int32_t);
 
-}  // namespace mozilla::gfx
+}  // namespace gfx
+}  // namespace mozilla
diff --git a/gfx/2d/SwizzleSSE2.cpp b/gfx/2d/SwizzleSSE2.cpp
index 297c81945c84..38e016809531 100644
--- a/gfx/2d/SwizzleSSE2.cpp
+++ b/gfx/2d/SwizzleSSE2.cpp
@@ -8,7 +8,8 @@
 
 #include <emmintrin.h>
 
-namespace mozilla::gfx {
+namespace mozilla {
+namespace gfx {
 
 // Load 1-3 pixels into a 4 pixel vector.
 static MOZ_ALWAYS_INLINE __m128i LoadRemainder_SSE2(const uint8_t* aSrc,
@@ -371,4 +372,5 @@ template void Swizzle_SSE2<true, false>(const uint8_t*, int32_t, uint8_t*,
 template void Swizzle_SSE2<true, true>(const uint8_t*, int32_t, uint8_t*,
                                        int32_t, IntSize);
 
-}  // namespace mozilla::gfx
+}  // namespace gfx
+}  // namespace mozilla
diff --git a/gfx/2d/SwizzleSSSE3.cpp b/gfx/2d/SwizzleSSSE3.cpp
index eac5d856fb6c..9a483c4fc10a 100644
--- a/gfx/2d/SwizzleSSSE3.cpp
+++ b/gfx/2d/SwizzleSSSE3.cpp
@@ -9,7 +9,8 @@
 #include <emmintrin.h>
 #include <tmmintrin.h>
 
-namespace mozilla::gfx {
+namespace mozilla {
+namespace gfx {
 
 template <bool aSwapRB>
 void UnpackRowRGB24(const uint8_t* aSrc, uint8_t* aDst, int32_t aLength);
@@ -62,4 +63,5 @@ void UnpackRowRGB24_SSSE3(const uint8_t* aSrc, uint8_t* aDst, int32_t aLength) {
 template void UnpackRowRGB24_SSSE3<false>(const uint8_t*, uint8_t*, int32_t);
 template void UnpackRowRGB24_SSSE3<true>(const uint8_t*, uint8_t*, int32_t);
 
-}  // namespace mozilla::gfx
+}  // namespace gfx
+}  // namespace mozilla
diff --git a/gfx/2d/UnscaledFontFreeType.cpp b/gfx/2d/UnscaledFontFreeType.cpp
index e73094b9672d..ffdf407d0ee2 100644
--- a/gfx/2d/UnscaledFontFreeType.cpp
+++ b/gfx/2d/UnscaledFontFreeType.cpp
@@ -20,7 +20,8 @@
 #include <sys/stat.h>
 #include <sys/mman.h>
 
-namespace mozilla::gfx {
+namespace mozilla {
+namespace gfx {
 
 bool UnscaledFontFreeType::GetFontFileData(FontFileDataOutput aDataCallback,
                                            void* aBaton) {
@@ -190,4 +191,5 @@ void UnscaledFontFreeType::ApplyVariationsToFace(
   }
 }
 
-}  // namespace mozilla::gfx
+}  // namespace gfx
+}  // namespace mozilla
diff --git a/gfx/gl/GLContextProviderGLX.cpp b/gfx/gl/GLContextProviderGLX.cpp
index b605492c93b3..cad050294f76 100644
--- a/gfx/gl/GLContextProviderGLX.cpp
+++ b/gfx/gl/GLContextProviderGLX.cpp
@@ -46,7 +46,8 @@
 #  include "gfxPlatformGtk.h"
 #endif
 
-namespace mozilla::gl {
+namespace mozilla {
+namespace gl {
 
 using namespace mozilla::gfx;
 using namespace mozilla::widget;
@@ -1051,4 +1052,5 @@ GLContext* GLContextProviderGLX::GetGlobalContext() {
 /*static*/
 void GLContextProviderGLX::Shutdown() {}
 
-}  // namespace mozilla::gl
+} /* namespace gl */
+} /* namespace mozilla */
diff --git a/gfx/gl/GLContextProviderWayland.cpp b/gfx/gl/GLContextProviderWayland.cpp
index c4c10bb4ffc2..b773802c7e51 100644
--- a/gfx/gl/GLContextProviderWayland.cpp
+++ b/gfx/gl/GLContextProviderWayland.cpp
@@ -10,7 +10,8 @@
 
 #include "GLContextProvider.h"
 
-namespace mozilla::gl {
+namespace mozilla {
+namespace gl {
 
 using namespace mozilla::gfx;
 using namespace mozilla::widget;
@@ -80,4 +81,5 @@ void GLContextProviderWayland::Shutdown() {
   }
 }
 
-}  // namespace mozilla::gl
+} /* namespace gl */
+} /* namespace mozilla */
diff --git a/gfx/gl/GLScreenBuffer.cpp b/gfx/gl/GLScreenBuffer.cpp
index be0f8736dcb0..ef34c71f4ad3 100644
--- a/gfx/gl/GLScreenBuffer.cpp
+++ b/gfx/gl/GLScreenBuffer.cpp
@@ -34,7 +34,8 @@
 #  include "SharedSurfaceGLX.h"
 #endif
 
-namespace mozilla::gl {
+namespace mozilla {
+namespace gl {
 
 using gfx::SurfaceFormat;
 
@@ -769,4 +770,5 @@ void ReadBuffer::SetReadBuffer(GLenum userMode) const {
   mGL->fReadBuffer(internalMode);
 }
 
-}  // namespace mozilla::gl
+} /* namespace gl */
+} /* namespace mozilla */
diff --git a/gfx/gl/SharedSurfaceGLX.cpp b/gfx/gl/SharedSurfaceGLX.cpp
index 43d1251d07fe..74ca442e307a 100644
--- a/gfx/gl/SharedSurfaceGLX.cpp
+++ b/gfx/gl/SharedSurfaceGLX.cpp
@@ -16,7 +16,8 @@
 #include "mozilla/layers/TextureForwarder.h"
 #include "mozilla/X11Util.h"
 
-namespace mozilla::gl {
+namespace mozilla {
+namespace gl {
 
 /* static */
 UniquePtr<SharedSurface_GLXDrawable> SharedSurface_GLXDrawable::Create(
@@ -118,4 +119,5 @@ UniquePtr<SharedSurface> SurfaceFactory_GLXDrawable::CreateShared(
                                            mAllocator->IsSameProcess());
 }
 
-}  // namespace mozilla::gl
+}  // namespace gl
+}  // namespace mozilla
diff --git a/gfx/ipc/GPUParent.cpp b/gfx/ipc/GPUParent.cpp
index cdf4292d7171..62c1592d20f9 100644
--- a/gfx/ipc/GPUParent.cpp
+++ b/gfx/ipc/GPUParent.cpp
@@ -73,7 +73,8 @@
 #  include "mozilla/SandboxTestingChild.h"
 #endif
 
-namespace mozilla::gfx {
+namespace mozilla {
+namespace gfx {
 
 using namespace ipc;
 using namespace layers;
@@ -586,4 +587,5 @@ void GPUParent::ActorDestroy(ActorDestroyReason aWhy) {
   XRE_ShutdownChildProcess();
 }
 
-}  // namespace mozilla::gfx
+}  // namespace gfx
+}  // namespace mozilla
diff --git a/gfx/layers/ImageContainer.cpp b/gfx/layers/ImageContainer.cpp
index a12f11c7772d..988f68b9cb7e 100644
--- a/gfx/layers/ImageContainer.cpp
+++ b/gfx/layers/ImageContainer.cpp
@@ -40,7 +40,8 @@
 #  include "mozilla/layers/D3D11YCbCrImage.h"
 #endif
 
-namespace mozilla::layers {
+namespace mozilla {
+namespace layers {
 
 using namespace mozilla::gfx;
 using namespace mozilla::ipc;
@@ -799,4 +800,5 @@ ImageContainer::ProducerID ImageContainer::AllocateProducerID() {
   return ++sProducerID;
 }
 
-}  // namespace mozilla::layers
+}  // namespace layers
+}  // namespace mozilla
diff --git a/gfx/layers/basic/BasicImageLayer.cpp b/gfx/layers/basic/BasicImageLayer.cpp
index c6a985610202..736663fd1e76 100644
--- a/gfx/layers/basic/BasicImageLayer.cpp
+++ b/gfx/layers/basic/BasicImageLayer.cpp
@@ -20,7 +20,8 @@
 
 using namespace mozilla::gfx;
 
-namespace mozilla::layers {
+namespace mozilla {
+namespace layers {
 
 class BasicImageLayer : public ImageLayer, public BasicImplData {
  public:
@@ -105,4 +106,5 @@ already_AddRefed<ImageLayer> BasicLayerManager::CreateImageLayer() {
   return layer.forget();
 }
 
-}  // namespace mozilla::layers
+}  // namespace layers
+}  // namespace mozilla
diff --git a/gfx/layers/basic/TextureClientX11.cpp b/gfx/layers/basic/TextureClientX11.cpp
index 68771d302661..dcc8abb3cdcb 100644
--- a/gfx/layers/basic/TextureClientX11.cpp
+++ b/gfx/layers/basic/TextureClientX11.cpp
@@ -22,7 +22,8 @@
 using namespace mozilla;
 using namespace mozilla::gfx;
 
-namespace mozilla::layers {
+namespace mozilla {
+namespace layers {
 
 X11TextureData::X11TextureData(gfx::IntSize aSize, gfx::SurfaceFormat aFormat,
                                bool aClientDeallocation, bool aIsCrossProcess,
@@ -136,4 +137,5 @@ X11TextureData* X11TextureData::Create(gfx::IntSize aSize,
   return texture;
 }
 
-}  // namespace mozilla::layers
+}  // namespace layers
+}  // namespace mozilla
diff --git a/gfx/layers/basic/X11TextureSourceBasic.cpp b/gfx/layers/basic/X11TextureSourceBasic.cpp
index b987f1ba1b3c..2e5effc10b18 100644
--- a/gfx/layers/basic/X11TextureSourceBasic.cpp
+++ b/gfx/layers/basic/X11TextureSourceBasic.cpp
@@ -8,7 +8,8 @@
 #include "gfxXlibSurface.h"
 #include "gfx2DGlue.h"
 
-namespace mozilla::layers {
+namespace mozilla {
+namespace layers {
 
 using namespace mozilla::gfx;
 
@@ -45,4 +46,5 @@ SurfaceFormat X11TextureSourceBasic::ContentTypeToSurfaceFormat(
   }
 }
 
-}  // namespace mozilla::layers
+}  // namespace layers
+}  // namespace mozilla
diff --git a/gfx/layers/client/TextureClient.cpp b/gfx/layers/client/TextureClient.cpp
index bace40221d52..73cc79a26d64 100644
--- a/gfx/layers/client/TextureClient.cpp
+++ b/gfx/layers/client/TextureClient.cpp
@@ -70,7 +70,8 @@
     } while (0)
 #endif
 
-namespace mozilla::layers {
+namespace mozilla {
+namespace layers {
 
 using namespace mozilla::ipc;
 using namespace mozilla::gl;
@@ -1906,4 +1907,5 @@ bool MappedYCbCrChannelData::CopyInto(MappedYCbCrChannelData& aDst) {
   return true;
 }
 
-}  // namespace mozilla::layers
+}  // namespace layers
+}  // namespace mozilla
diff --git a/gfx/layers/composite/X11TextureHost.cpp b/gfx/layers/composite/X11TextureHost.cpp
index 5bbb7a82c85b..dbbbb4300e76 100644
--- a/gfx/layers/composite/X11TextureHost.cpp
+++ b/gfx/layers/composite/X11TextureHost.cpp
@@ -14,7 +14,8 @@
 #include "gfxPlatform.h"
 #include "gfxXlibSurface.h"
 
-namespace mozilla::layers {
+namespace mozilla {
+namespace layers {
 
 using namespace mozilla::gfx;
 
@@ -100,4 +101,5 @@ already_AddRefed<gfx::DataSourceSurface> X11TextureHost::GetAsSurface() {
   return surf->GetDataSurface();
 }
 
-}  // namespace mozilla::layers
+}  // namespace layers
+}  // namespace mozilla
diff --git a/gfx/layers/opengl/WaylandDMABUFTextureClientOGL.cpp b/gfx/layers/opengl/WaylandDMABUFTextureClientOGL.cpp
index 9ab5d2b563fc..02b825fa3443 100644
--- a/gfx/layers/opengl/WaylandDMABUFTextureClientOGL.cpp
+++ b/gfx/layers/opengl/WaylandDMABUFTextureClientOGL.cpp
@@ -8,7 +8,8 @@
 #include "mozilla/widget/WaylandDMABufSurface.h"
 #include "gfxPlatform.h"
 
-namespace mozilla::layers {
+namespace mozilla {
+namespace layers {
 
 using namespace gfx;
 
@@ -102,4 +103,5 @@ bool WaylandDMABUFTextureData::UpdateFromSurface(gfx::SourceSurface* aSurface) {
   return true;
 }
 
-}  // namespace mozilla::layers
+}  // namespace layers
+}  // namespace mozilla
diff --git a/gfx/layers/opengl/WaylandDMABUFTextureHostOGL.cpp b/gfx/layers/opengl/WaylandDMABUFTextureHostOGL.cpp
index 0e945d9b642d..aa86a9bb9f72 100644
--- a/gfx/layers/opengl/WaylandDMABUFTextureHostOGL.cpp
+++ b/gfx/layers/opengl/WaylandDMABUFTextureHostOGL.cpp
@@ -11,7 +11,8 @@
 #include "mozilla/webrender/WebRenderAPI.h"
 #include "GLContextEGL.h"
 
-namespace mozilla::layers {
+namespace mozilla {
+namespace layers {
 
 WaylandDMABUFTextureHostOGL::WaylandDMABUFTextureHostOGL(
     TextureFlags aFlags, const SurfaceDescriptor& aDesc)
@@ -134,4 +135,5 @@ void WaylandDMABUFTextureHostOGL::PushDisplayItems(
                      !(mFlags & TextureFlags::NON_PREMULTIPLIED));
 }
 
-}  // namespace mozilla::layers
+}  // namespace layers
+}  // namespace mozilla
diff --git a/gfx/layers/opengl/X11TextureSourceOGL.cpp b/gfx/layers/opengl/X11TextureSourceOGL.cpp
index d0c9db0fd2cd..968cc79e803b 100644
--- a/gfx/layers/opengl/X11TextureSourceOGL.cpp
+++ b/gfx/layers/opengl/X11TextureSourceOGL.cpp
@@ -9,7 +9,8 @@
 #include "gfx2DGlue.h"
 #include "GLContext.h"
 
-namespace mozilla::layers {
+namespace mozilla {
+namespace layers {
 
 using namespace mozilla::gfx;
 
@@ -86,4 +87,5 @@ SurfaceFormat X11TextureSourceOGL::ContentTypeToSurfaceFormat(
   }
 }
 
-}  // namespace mozilla::layers
+}  // namespace layers
+}  // namespace mozilla
diff --git a/gfx/layers/wr/WebRenderTextureHost.cpp b/gfx/layers/wr/WebRenderTextureHost.cpp
index aae301152e28..aec3d4dc8385 100644
--- a/gfx/layers/wr/WebRenderTextureHost.cpp
+++ b/gfx/layers/wr/WebRenderTextureHost.cpp
@@ -15,7 +15,8 @@
 #  include "mozilla/layers/TextureHostOGL.h"
 #endif
 
-namespace mozilla::layers {
+namespace mozilla {
+namespace layers {
 
 WebRenderTextureHost::WebRenderTextureHost(
     const SurfaceDescriptor& aDesc, TextureFlags aFlags, TextureHost* aTexture,
@@ -229,4 +230,5 @@ bool WebRenderTextureHost::NeedsYFlip() const {
   return yFlip;
 }
 
-}  // namespace mozilla::layers
+}  // namespace layers
+}  // namespace mozilla
diff --git a/gfx/thebes/PrintTarget.cpp b/gfx/thebes/PrintTarget.cpp
index 3960ff26605a..907a6deed269 100644
--- a/gfx/thebes/PrintTarget.cpp
+++ b/gfx/thebes/PrintTarget.cpp
@@ -23,7 +23,8 @@
 // RFC: https://tools.ietf.org/html/rfc2911#section-4.1.2
 #define IPP_JOB_NAME_LIMIT_LENGTH 255
 
-namespace mozilla::gfx {
+namespace mozilla {
+namespace gfx {
 
 PrintTarget::PrintTarget(cairo_surface_t* aCairoSurface, const IntSize& aSize)
     : mCairoSurface(aCairoSurface),
@@ -201,4 +202,5 @@ void PrintTarget::RegisterPageDoneCallback(PageDoneCallback&& aCallback) {
 
 void PrintTarget::UnregisterPageDoneCallback() { mPageDoneCallback = nullptr; }
 
-}  // namespace mozilla::gfx
+}  // namespace gfx
+}  // namespace mozilla
diff --git a/gfx/thebes/PrintTargetPDF.cpp b/gfx/thebes/PrintTargetPDF.cpp
index 8dd98ff569ec..fe97bbcd3026 100644
--- a/gfx/thebes/PrintTargetPDF.cpp
+++ b/gfx/thebes/PrintTargetPDF.cpp
@@ -8,7 +8,8 @@
 #include "cairo.h"
 #include "cairo-pdf.h"
 
-namespace mozilla::gfx {
+namespace mozilla {
+namespace gfx {
 
 static cairo_status_t write_func(void* closure, const unsigned char* data,
                                  unsigned int length) {
@@ -68,4 +69,5 @@ void PrintTargetPDF::Finish() {
   mStream->Close();
 }
 
-}  // namespace mozilla::gfx
+}  // namespace gfx
+}  // namespace mozilla
diff --git a/gfx/thebes/PrintTargetPS.cpp b/gfx/thebes/PrintTargetPS.cpp
index cc2d94bcb8c1..3b888bd1983b 100644
--- a/gfx/thebes/PrintTargetPS.cpp
+++ b/gfx/thebes/PrintTargetPS.cpp
@@ -8,7 +8,8 @@
 #include "cairo.h"
 #include "cairo-ps.h"
 
-namespace mozilla::gfx {
+namespace mozilla {
+namespace gfx {
 
 static cairo_status_t write_func(void* closure, const unsigned char* data,
                                  unsigned int length) {
@@ -93,4 +94,5 @@ void PrintTargetPS::Finish() {
   mStream->Close();
 }
 
-}  // namespace mozilla::gfx
+}  // namespace gfx
+}  // namespace mozilla
diff --git a/gfx/thebes/PrintTargetSkPDF.cpp b/gfx/thebes/PrintTargetSkPDF.cpp
index 4c7af1644b31..29cb48d6c651 100644
--- a/gfx/thebes/PrintTargetSkPDF.cpp
+++ b/gfx/thebes/PrintTargetSkPDF.cpp
@@ -9,7 +9,8 @@
 #include "nsString.h"
 #include <vector>
 
-namespace mozilla::gfx {
+namespace mozilla {
+namespace gfx {
 
 PrintTargetSkPDF::PrintTargetSkPDF(const IntSize& aSize,
                                    UniquePtr<SkWStream> aStream)
@@ -123,4 +124,5 @@ already_AddRefed<DrawTarget> PrintTargetSkPDF::GetReferenceDrawTarget() {
   return do_AddRef(mRefDT);
 }
 
-}  // namespace mozilla::gfx
+}  // namespace gfx
+}  // namespace mozilla
diff --git a/gfx/thebes/PrintTargetThebes.cpp b/gfx/thebes/PrintTargetThebes.cpp
index 8516e1aac2f5..8a066d5690a3 100644
--- a/gfx/thebes/PrintTargetThebes.cpp
+++ b/gfx/thebes/PrintTargetThebes.cpp
@@ -9,7 +9,8 @@
 #include "gfxPlatform.h"
 #include "mozilla/gfx/Logging.h"
 
-namespace mozilla::gfx {
+namespace mozilla {
+namespace gfx {
 
 /* static */
 already_AddRefed<PrintTargetThebes> PrintTargetThebes::CreateOrNull(
@@ -95,4 +96,5 @@ nsresult PrintTargetThebes::EndPage() {
 
 void PrintTargetThebes::Finish() { return mGfxSurface->Finish(); }
 
-}  // namespace mozilla::gfx
+}  // namespace gfx
+}  // namespace mozilla
diff --git a/gfx/vr/VRManager.cpp b/gfx/vr/VRManager.cpp
index 28d5bcdfe1d6..948f03459fda 100644
--- a/gfx/vr/VRManager.cpp
+++ b/gfx/vr/VRManager.cpp
@@ -48,7 +48,8 @@ using namespace mozilla::gfx;
 using namespace mozilla::layers;
 using namespace mozilla::gl;
 
-namespace mozilla::gfx {
+namespace mozilla {
+namespace gfx {
 
 /**
  * When VR content is active, we run the tasks at 1ms
@@ -1530,4 +1531,5 @@ VRManager::Observe(nsISupports* subject, const char* topic,
 
 NS_IMPL_ISUPPORTS(VRManager, nsIObserver)
 
-}  // namespace mozilla::gfx
+}  // namespace gfx
+}  // namespace mozilla
diff --git a/gfx/vr/VRPuppetCommandBuffer.cpp b/gfx/vr/VRPuppetCommandBuffer.cpp
index 6338d77fdd1a..d73bf30482a0 100644
--- a/gfx/vr/VRPuppetCommandBuffer.cpp
+++ b/gfx/vr/VRPuppetCommandBuffer.cpp
@@ -8,7 +8,8 @@
 #include "prthread.h"
 #include "mozilla/ClearOnShutdown.h"
 
-namespace mozilla::gfx {
+namespace mozilla {
+namespace gfx {
 
 static StaticRefPtr<VRPuppetCommandBuffer> sVRPuppetCommandBufferSingleton;
 
@@ -507,4 +508,5 @@ void VRPuppetCommandBuffer::EncodeStruct(nsTArray<uint64_t>& aBuffer,
   purgeBuffer();
 }
 
-}  // namespace mozilla::gfx
+}  // namespace gfx
+}  // namespace mozilla
diff --git a/gfx/vr/ipc/VRLayerChild.cpp b/gfx/vr/ipc/VRLayerChild.cpp
index ed2815261bcc..d0d3afcb5b6c 100644
--- a/gfx/vr/ipc/VRLayerChild.cpp
+++ b/gfx/vr/ipc/VRLayerChild.cpp
@@ -16,7 +16,8 @@
 #include "mozilla/dom/HTMLCanvasElement.h"
 #include "mozilla/layers/SyncObject.h"  // for SyncObjectClient
 
-namespace mozilla::gfx {
+namespace mozilla {
+namespace gfx {
 
 VRLayerChild::VRLayerChild()
     : mCanvasElement(nullptr), mIPCOpen(false), mLastSubmittedFrameId(0) {
@@ -139,4 +140,5 @@ void VRLayerChild::ReleaseIPDLReference() {
   Release();
 }
 
-}  // namespace mozilla::gfx
+}  // namespace gfx
+}  // namespace mozilla
diff --git a/gfx/vr/service/OpenVRSession.cpp b/gfx/vr/service/OpenVRSession.cpp
index dc601063b412..ca934860a86b 100644
--- a/gfx/vr/service/OpenVRSession.cpp
+++ b/gfx/vr/service/OpenVRSession.cpp
@@ -51,7 +51,8 @@ const uint32_t kVRHapticUpdateInterval = 5;
 
 using namespace mozilla::gfx;
 
-namespace mozilla::gfx {
+namespace mozilla {
+namespace gfx {
 
 namespace {
 
@@ -2363,4 +2364,5 @@ void OpenVRSession::UpdateTelemetry(VRSystemState& aSystemState) {
   aSystemState.displayState.droppedFrameCount = stats.m_nNumReprojectedFrames;
 }
 
-}  // namespace mozilla::gfx
+}  // namespace gfx
+}  // namespace mozilla
diff --git a/gfx/vr/service/PuppetSession.cpp b/gfx/vr/service/PuppetSession.cpp
index c8b81b4a405c..8a8188b06abf 100644
--- a/gfx/vr/service/PuppetSession.cpp
+++ b/gfx/vr/service/PuppetSession.cpp
@@ -19,7 +19,8 @@
 
 using namespace mozilla::gfx;
 
-namespace mozilla::gfx {
+namespace mozilla {
+namespace gfx {
 
 PuppetSession::PuppetSession() : VRSession() {}
 
@@ -115,4 +116,5 @@ void PuppetSession::StopAllHaptics() {
   VRPuppetCommandBuffer::Get().StopAllHaptics();
 }
 
-}  // namespace mozilla::gfx
+}  // namespace gfx
+}  // namespace mozilla
diff --git a/gfx/webrender_bindings/RenderCompositorEGL.cpp b/gfx/webrender_bindings/RenderCompositorEGL.cpp
index 8ee25cb67d14..ed9bbda9dede 100644
--- a/gfx/webrender_bindings/RenderCompositorEGL.cpp
+++ b/gfx/webrender_bindings/RenderCompositorEGL.cpp
@@ -26,7 +26,8 @@
 #  include <android/native_window_jni.h>
 #endif
 
-namespace mozilla::wr {
+namespace mozilla {
+namespace wr {
 
 /* static */
 UniquePtr<RenderCompositor> RenderCompositorEGL::Create(
@@ -119,7 +120,7 @@ bool RenderCompositorEGL::Resume() {
   EGLNativeWindowType window = mWidget->AsAndroid()->GetEGLNativeWindow();
   JNIEnv* const env = jni::GetEnvForThread();
   ANativeWindow* const nativeWindow =
-      ANativeWindow_fromSurface(env, reinterpret_cast<jobject>(window));
+    ANativeWindow_fromSurface(env, reinterpret_cast<jobject>(window));
   const int32_t width = ANativeWindow_getWidth(nativeWindow);
   const int32_t height = ANativeWindow_getHeight(nativeWindow);
   mEGLSurfaceSize = LayoutDeviceIntSize(width, height);
@@ -175,4 +176,5 @@ LayoutDeviceIntSize RenderCompositorEGL::GetBufferSize() {
 #endif
 }
 
-}  // namespace mozilla::wr
+}  // namespace wr
+}  // namespace mozilla
diff --git a/gfx/webrender_bindings/RenderWaylandDMABUFTextureHostOGL.cpp b/gfx/webrender_bindings/RenderWaylandDMABUFTextureHostOGL.cpp
index 419e4c816af5..da5de53d1d69 100644
--- a/gfx/webrender_bindings/RenderWaylandDMABUFTextureHostOGL.cpp
+++ b/gfx/webrender_bindings/RenderWaylandDMABUFTextureHostOGL.cpp
@@ -10,7 +10,8 @@
 #include "mozilla/gfx/Logging.h"
 #include "ScopedGLHelpers.h"
 
-namespace mozilla::wr {
+namespace mozilla {
+namespace wr {
 
 RenderWaylandDMABUFTextureHostOGL::RenderWaylandDMABUFTextureHostOGL(
     WaylandDMABufSurface* aSurface)
@@ -90,4 +91,5 @@ void RenderWaylandDMABUFTextureHostOGL::DeleteTextureHandle() {
   }
 }
 
-}  // namespace mozilla::wr
+}  // namespace wr
+}  // namespace mozilla
diff --git a/hal/Hal.cpp b/hal/Hal.cpp
index f3646b3a9b3b..5f99271db9df 100644
--- a/hal/Hal.cpp
+++ b/hal/Hal.cpp
@@ -51,7 +51,8 @@ using namespace mozilla::dom;
     }                                              \
   } while (0)
 
-namespace mozilla::hal {
+namespace mozilla {
+namespace hal {
 
 static bool sInitialized = false;
 
@@ -479,4 +480,5 @@ void Shutdown() {
   sInitialized = false;
 }
 
-}  // namespace mozilla::hal
+}  // namespace hal
+}  // namespace mozilla
diff --git a/ipc/glue/BackgroundChildImpl.cpp b/ipc/glue/BackgroundChildImpl.cpp
index 1a650ea46df1..68470941ba2c 100644
--- a/ipc/glue/BackgroundChildImpl.cpp
+++ b/ipc/glue/BackgroundChildImpl.cpp
@@ -80,7 +80,8 @@ class TestChild final : public mozilla::ipc::PBackgroundTestChild {
 
 }  // namespace
 
-namespace mozilla::ipc {
+namespace mozilla {
+namespace ipc {
 
 using mozilla::dom::UDPSocketChild;
 using mozilla::net::PUDPSocketChild;
@@ -756,7 +757,8 @@ PFileDescriptorSetChild* BackgroundChildImpl::SendPFileDescriptorSetConstructor(
   return PBackgroundChild::SendPFileDescriptorSetConstructor(aFD);
 }
 
-}  // namespace mozilla::ipc
+}  // namespace ipc
+}  // namespace mozilla
 
 mozilla::ipc::IPCResult TestChild::Recv__delete__(const nsCString& aTestArg) {
   MOZ_RELEASE_ASSERT(aTestArg == mTestArg,
diff --git a/ipc/glue/BackgroundParentImpl.cpp b/ipc/glue/BackgroundParentImpl.cpp
index 668d254eb107..a3a5cdff40f1 100644
--- a/ipc/glue/BackgroundParentImpl.cpp
+++ b/ipc/glue/BackgroundParentImpl.cpp
@@ -112,7 +112,8 @@ class TestParent final : public mozilla::ipc::PBackgroundTestParent {
 
 }  // namespace
 
-namespace mozilla::ipc {
+namespace mozilla {
+namespace ipc {
 
 using mozilla::dom::BroadcastChannelParent;
 using mozilla::dom::ContentParent;
@@ -1304,7 +1305,8 @@ BackgroundParentImpl::SendPFileDescriptorSetConstructor(
   return PBackgroundParent::SendPFileDescriptorSetConstructor(aFD);
 }
 
-}  // namespace mozilla::ipc
+}  // namespace ipc
+}  // namespace mozilla
 
 void TestParent::ActorDestroy(ActorDestroyReason aWhy) {
   mozilla::ipc::AssertIsInMainOrSocketProcess();
diff --git a/ipc/glue/FileDescriptorSetChild.cpp b/ipc/glue/FileDescriptorSetChild.cpp
index 8f2f062e5bda..8a1b3f38c719 100644
--- a/ipc/glue/FileDescriptorSetChild.cpp
+++ b/ipc/glue/FileDescriptorSetChild.cpp
@@ -6,7 +6,8 @@
 
 #include "FileDescriptorSetChild.h"
 
-namespace mozilla::ipc {
+namespace mozilla {
+namespace ipc {
 
 FileDescriptorSetChild::FileDescriptorSetChild(
     const FileDescriptor& aFileDescriptor) {
@@ -29,4 +30,5 @@ mozilla::ipc::IPCResult FileDescriptorSetChild::RecvAddFileDescriptor(
   return IPC_OK();
 }
 
-}  // namespace mozilla::ipc
+}  // namespace ipc
+}  // namespace mozilla
diff --git a/ipc/glue/FileDescriptorSetParent.cpp b/ipc/glue/FileDescriptorSetParent.cpp
index 3c42ea681e90..583b183b215e 100644
--- a/ipc/glue/FileDescriptorSetParent.cpp
+++ b/ipc/glue/FileDescriptorSetParent.cpp
@@ -6,7 +6,8 @@
 
 #include "FileDescriptorSetParent.h"
 
-namespace mozilla::ipc {
+namespace mozilla {
+namespace ipc {
 
 FileDescriptorSetParent::FileDescriptorSetParent(
     const FileDescriptor& aFileDescriptor) {
@@ -31,4 +32,5 @@ mozilla::ipc::IPCResult FileDescriptorSetParent::RecvAddFileDescriptor(
   return IPC_OK();
 }
 
-}  // namespace mozilla::ipc
+}  // namespace ipc
+}  // namespace mozilla
diff --git a/js/ductwork/debugger/JSDebugger.cpp b/js/ductwork/debugger/JSDebugger.cpp
index 47803585605e..cebfafefedd3 100644
--- a/js/ductwork/debugger/JSDebugger.cpp
+++ b/js/ductwork/debugger/JSDebugger.cpp
@@ -21,7 +21,8 @@
     }                                                \
   }
 
-namespace mozilla::jsdebugger {
+namespace mozilla {
+namespace jsdebugger {
 
 NS_IMPL_ISUPPORTS(JSDebugger, IJSDebugger)
 
@@ -68,4 +69,5 @@ JSDebugger::AddClass(JS::Handle<JS::Value> global, JSContext* cx) {
   return NS_OK;
 }
 
-}  // namespace mozilla::jsdebugger
+}  // namespace jsdebugger
+}  // namespace mozilla
diff --git a/js/src/ctypes/CTypes.cpp b/js/src/ctypes/CTypes.cpp
index fca6ff9a9e14..ba57455323b4 100644
--- a/js/src/ctypes/CTypes.cpp
+++ b/js/src/ctypes/CTypes.cpp
@@ -64,7 +64,8 @@ using mozilla::IsAsciiDigit;
 using JS::AutoCheckCannotGC;
 using JS::AutoStableStringChars;
 
-namespace js::ctypes {
+namespace js {
+namespace ctypes {
 
 static bool HasUnpairedSurrogate(const char16_t* chars, size_t nchars,
                                  char16_t* unpaired) {
@@ -2318,7 +2319,8 @@ static bool GetObjectProperty(JSContext* cx, HandleObject obj,
   return true;
 }
 
-}  // namespace js::ctypes
+} /* namespace ctypes */
+} /* namespace js */
 
 using namespace js;
 using namespace js::ctypes;
diff --git a/js/src/ctypes/Library.cpp b/js/src/ctypes/Library.cpp
index 9455b1c956f4..4a7b1eaa78b7 100644
--- a/js/src/ctypes/Library.cpp
+++ b/js/src/ctypes/Library.cpp
@@ -17,7 +17,8 @@
 
 using JS::AutoStableStringChars;
 
-namespace js::ctypes {
+namespace js {
+namespace ctypes {
 
 /*******************************************************************************
 ** JSAPI function prototypes
@@ -402,4 +403,5 @@ bool Library::Declare(JSContext* cx, unsigned argc, Value* vp) {
   return true;
 }
 
-}  // namespace js::ctypes
+}  // namespace ctypes
+}  // namespace js
diff --git a/js/src/frontend/BinASTParser.cpp b/js/src/frontend/BinASTParser.cpp
index dc1a19ed3fd3..1a98728baa39 100644
--- a/js/src/frontend/BinASTParser.cpp
+++ b/js/src/frontend/BinASTParser.cpp
@@ -33,7 +33,8 @@
 using JS::RegExpFlag;
 using JS::RegExpFlags;
 
-namespace js::frontend {
+namespace js {
+namespace frontend {
 
 // Compare a bunch of `uint8_t` values (as returned by the tokenizer_) with
 // a string literal (and ONLY a string literal).
@@ -5035,4 +5036,5 @@ JS::Result<ParseNode*> BinASTParser<Tok>::parseOptionalStatement(
 template class BinASTParser<BinASTTokenReaderContext>;
 template class BinASTParser<BinASTTokenReaderMultipart>;
 
-}  // namespace js::frontend
+}  // namespace frontend
+}  // namespace js
diff --git a/js/src/frontend/BinASTParserBase.cpp b/js/src/frontend/BinASTParserBase.cpp
index db51bdb5fe00..d00e3c6e4cc3 100644
--- a/js/src/frontend/BinASTParserBase.cpp
+++ b/js/src/frontend/BinASTParserBase.cpp
@@ -8,11 +8,13 @@
 
 #include "vm/JSContext-inl.h"
 
-namespace js::frontend {
+namespace js {
+namespace frontend {
 
 BinASTParserBase::BinASTParserBase(JSContext* cx, ParseInfo& parseInfo,
                                    HandleScriptSourceObject sourceObject)
     : ParserSharedBase(cx, parseInfo, sourceObject,
                        ParserSharedBase::Kind::BinASTParser) {}
 
-}  // namespace js::frontend
+}  // namespace frontend
+}  // namespace js
diff --git a/js/src/frontend/BinASTParserPerTokenizer.cpp b/js/src/frontend/BinASTParserPerTokenizer.cpp
index 4e774a4187e3..3e4bde7f0227 100644
--- a/js/src/frontend/BinASTParserPerTokenizer.cpp
+++ b/js/src/frontend/BinASTParserPerTokenizer.cpp
@@ -74,7 +74,8 @@
 //
 // They should be treated lazily (whenever we open a subscope), like bindings.
 
-namespace js::frontend {
+namespace js {
+namespace frontend {
 
 using UsedNamePtr = UsedNameTracker::UsedNameMap::Ptr;
 
@@ -810,4 +811,5 @@ BinASTParserPerTokenizer<Tok>::asFinalParser() const {
 template class BinASTParserPerTokenizer<BinASTTokenReaderContext>;
 template class BinASTParserPerTokenizer<BinASTTokenReaderMultipart>;
 
-}  // namespace js::frontend
+}  // namespace frontend
+}  // namespace js
diff --git a/js/src/frontend/BinASTRuntimeSupport.cpp b/js/src/frontend/BinASTRuntimeSupport.cpp
index 5da6001ef862..a04569a2de1b 100644
--- a/js/src/frontend/BinASTRuntimeSupport.cpp
+++ b/js/src/frontend/BinASTRuntimeSupport.cpp
@@ -12,7 +12,8 @@
 #include "js/Utility.h"     // js_malloc
 #include "vm/StringType.h"  // JSAtom
 
-namespace js::frontend {
+namespace js {
+namespace frontend {
 
 BinASTSourceMetadata::~BinASTSourceMetadata() {
   if (isMultipart()) {
@@ -110,4 +111,6 @@ void BinASTSourceMetadataContext::release() {
   }
 }
 
-}  // namespace js::frontend
+}  // namespace frontend
+
+}  // namespace js
diff --git a/js/src/frontend/BinASTTokenReaderBase.cpp b/js/src/frontend/BinASTTokenReaderBase.cpp
index ef1f8e3962a5..575aed875fb3 100644
--- a/js/src/frontend/BinASTTokenReaderBase.cpp
+++ b/js/src/frontend/BinASTTokenReaderBase.cpp
@@ -9,7 +9,8 @@
 #include "frontend/BinAST-macros.h"
 #include "js/Result.h"
 
-namespace js::frontend {
+namespace js {
+namespace frontend {
 
 template <typename T>
 using ErrorResult = mozilla::GenericErrorResult<T>;
@@ -104,4 +105,5 @@ JS::Result<uint8_t> BinASTTokenReaderBase::readByte() {
   return *current_++;
 }
 
-}  // namespace js::frontend
+}  // namespace frontend
+}  // namespace js
diff --git a/js/src/frontend/BinASTTokenReaderContext.cpp b/js/src/frontend/BinASTTokenReaderContext.cpp
index bc7582c0fe27..5befb5cabc3f 100644
--- a/js/src/frontend/BinASTTokenReaderContext.cpp
+++ b/js/src/frontend/BinASTTokenReaderContext.cpp
@@ -26,7 +26,8 @@
 #include "vm/JSAtom.h"               // AtomizeWTF8Chars
 #include "vm/JSScript.h"             // ScriptSource
 
-namespace js::frontend {
+namespace js {
+namespace frontend {
 
 #ifdef BINAST_CX_MAGIC_HEADER  // Context 0.1 doesn't implement the planned
                                // magic header.
@@ -3268,4 +3269,6 @@ mozilla::detail::IntegerRange<size_t> HuffmanLookup::suffixes(
   return mozilla::IntegerRange<size_t>(first, last + 1);
 }
 
-}  // namespace js::frontend
+}  // namespace frontend
+
+}  // namespace js
diff --git a/js/src/frontend/BinASTTokenReaderMultipart.cpp b/js/src/frontend/BinASTTokenReaderMultipart.cpp
index 86d1eb4d2f07..e419a9755db3 100644
--- a/js/src/frontend/BinASTTokenReaderMultipart.cpp
+++ b/js/src/frontend/BinASTTokenReaderMultipart.cpp
@@ -20,7 +20,8 @@
 
 #include "js/Result.h"
 
-namespace js::frontend {
+namespace js {
+namespace frontend {
 
 // The magic header, at the start of every binjs file.
 const char MAGIC_HEADER[] = "BINJS";
@@ -473,4 +474,6 @@ JS::Result<Ok> BinASTTokenReaderMultipart::AutoTaggedTuple::done() {
   return Ok();
 }
 
-}  // namespace js::frontend
+}  // namespace frontend
+
+}  // namespace js
diff --git a/js/src/frontend/Parser.cpp b/js/src/frontend/Parser.cpp
index 2c6b445ee785..64d037d50b27 100644
--- a/js/src/frontend/Parser.cpp
+++ b/js/src/frontend/Parser.cpp
@@ -79,7 +79,8 @@ using JS::AutoGCRooter;
 using JS::ReadOnlyCompileOptions;
 using JS::RegExpFlags;
 
-namespace js::frontend {
+namespace js {
+namespace frontend {
 
 using DeclaredNamePtr = ParseContext::Scope::DeclaredNamePtr;
 using AddDeclaredNamePtr = ParseContext::Scope::AddDeclaredNamePtr;
@@ -10874,4 +10875,5 @@ template class Parser<SyntaxParseHandler, Utf8Unit>;
 template class Parser<FullParseHandler, char16_t>;
 template class Parser<SyntaxParseHandler, char16_t>;
 
-}  // namespace js::frontend
+} /* namespace frontend */
+} /* namespace js */
diff --git a/js/src/vtune/VTuneWrapper.cpp b/js/src/vtune/VTuneWrapper.cpp
index d677b64fffe8..d96a56b48490 100644
--- a/js/src/vtune/VTuneWrapper.cpp
+++ b/js/src/vtune/VTuneWrapper.cpp
@@ -15,7 +15,8 @@
 #include "vm/Realm.h"
 #include "vm/Shape.h"
 
-namespace js::vtune {
+namespace js {
+namespace vtune {
 
 // VTune internals are not known to be threadsafe.
 static Mutex* VTuneMutex = nullptr;
@@ -160,4 +161,5 @@ void UnmarkBytes(void* bytes, unsigned size) {
   if (ok != 1) printf("[!] VTune Integration: Failed to unload method.\n");
 }
 
-}  // namespace js::vtune
+}  // namespace vtune
+}  // namespace js
diff --git a/layout/ipc/VsyncChild.cpp b/layout/ipc/VsyncChild.cpp
index c1e9908f78c8..ec3662c2f3e7 100644
--- a/layout/ipc/VsyncChild.cpp
+++ b/layout/ipc/VsyncChild.cpp
@@ -10,7 +10,8 @@
 #include "mozilla/VsyncDispatcher.h"
 #include "nsThreadUtils.h"
 
-namespace mozilla::layout {
+namespace mozilla {
+namespace layout {
 
 VsyncChild::VsyncChild()
     : mObservingVsync(false),
@@ -90,4 +91,5 @@ mozilla::ipc::IPCResult VsyncChild::RecvVsyncRate(const float& aVsyncRate) {
   return IPC_OK();
 }
 
-}  // namespace mozilla::layout
+}  // namespace layout
+}  // namespace mozilla
diff --git a/media/mtransport/WebrtcTCPSocketWrapper.cpp b/media/mtransport/WebrtcTCPSocketWrapper.cpp
index 11bda0cd2ccb..e72cf0beb614 100644
--- a/media/mtransport/WebrtcTCPSocketWrapper.cpp
+++ b/media/mtransport/WebrtcTCPSocketWrapper.cpp
@@ -15,7 +15,8 @@
 
 #include "nr_socket_proxy_config.h"
 
-namespace mozilla::net {
+namespace mozilla {
+namespace net {
 
 using std::shared_ptr;
 
@@ -121,4 +122,5 @@ void WebrtcTCPSocketWrapper::OnConnected(const nsCString& aProxyType) {
       &WebrtcTCPSocketCallback::OnConnected, aProxyType)));
 }
 
-}  // namespace mozilla::net
+}  // namespace net
+}  // namespace mozilla
diff --git a/mfbt/RecordReplay.cpp b/mfbt/RecordReplay.cpp
index 2f0df117f498..2de37fe4b172 100644
--- a/mfbt/RecordReplay.cpp
+++ b/mfbt/RecordReplay.cpp
@@ -22,7 +22,8 @@
 #  include <dlfcn.h>
 #endif
 
-namespace mozilla::recordreplay {
+namespace mozilla {
+namespace recordreplay {
 
 // clang-format off
 #define FOR_EACH_INTERFACE(Macro)                                              \
@@ -179,4 +180,5 @@ bool gIsMiddleman;
 
 #undef ENABLE_RECORD_REPLAY
 
-}  // namespace mozilla::recordreplay
+}  // namespace recordreplay
+}  // namespace mozilla
diff --git a/netwerk/base/NetworkInfoServiceLinux.cpp b/netwerk/base/NetworkInfoServiceLinux.cpp
index 9b42ad6dbdb5..13fb0dbea7da 100644
--- a/netwerk/base/NetworkInfoServiceLinux.cpp
+++ b/netwerk/base/NetworkInfoServiceLinux.cpp
@@ -17,7 +17,8 @@
 
 #include "NetworkInfoServiceImpl.h"
 
-namespace mozilla::net {
+namespace mozilla {
+namespace net {
 
 static nsresult ListInterfaceAddresses(int aFd, const char* aIface,
                                        AddrMapType& aAddrMap);
@@ -93,4 +94,5 @@ static nsresult ListInterfaceAddresses(int aFd, const char* aInterface,
   return NS_OK;
 }
 
-}  // namespace mozilla::net
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/base/nsNetworkInfoService.cpp b/netwerk/base/nsNetworkInfoService.cpp
index 69610b9ef1c7..de891912b4ea 100644
--- a/netwerk/base/nsNetworkInfoService.cpp
+++ b/netwerk/base/nsNetworkInfoService.cpp
@@ -19,7 +19,8 @@
 #  error "Unsupported platform for nsNetworkInfoService!  Check moz.build"
 #endif
 
-namespace mozilla::net {
+namespace mozilla {
+namespace net {
 
 NS_IMPL_ISUPPORTS(nsNetworkInfoService, nsINetworkInfoService)
 
@@ -92,4 +93,5 @@ nsresult nsNetworkInfoService::GetHostname(nsIGetHostnameListener* aListener) {
   return NS_OK;
 }
 
-}  // namespace mozilla::net
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/build/nsNetModule.cpp b/netwerk/build/nsNetModule.cpp
index 13d5a8c6707d..1132ee45be88 100644
--- a/netwerk/build/nsNetModule.cpp
+++ b/netwerk/build/nsNetModule.cpp
@@ -81,7 +81,8 @@ nsresult nsCacheServiceConstructor(nsISupports* aOuter, const nsIID& aIID,
 
 #include "WebSocketChannel.h"
 #include "WebSocketChannelChild.h"
-namespace mozilla::net {
+namespace mozilla {
+namespace net {
 static BaseWebSocketChannel* WebSocketChannelConstructor(bool aSecure) {
   if (IsNeckoChild()) {
     return new WebSocketChannelChild(aSecure);
@@ -112,7 +113,8 @@ static BaseWebSocketChannel* WebSocketChannelConstructor(bool aSecure) {
 WEB_SOCKET_HANDLER_CONSTRUCTOR(WebSocketChannel, false)
 WEB_SOCKET_HANDLER_CONSTRUCTOR(WebSocketSSLChannel, true)
 #undef WEB_SOCKET_HANDLER_CONSTRUCTOR
-}  // namespace mozilla::net
+}  // namespace net
+}  // namespace mozilla
 
 ///////////////////////////////////////////////////////////////////////////////
 
diff --git a/netwerk/cache2/AppCacheStorage.cpp b/netwerk/cache2/AppCacheStorage.cpp
index cf8bb36c794a..c81258dce4db 100644
--- a/netwerk/cache2/AppCacheStorage.cpp
+++ b/netwerk/cache2/AppCacheStorage.cpp
@@ -19,7 +19,8 @@
 #include "nsServiceManagerUtils.h"
 #include "nsThreadUtils.h"
 
-namespace mozilla::net {
+namespace mozilla {
+namespace net {
 
 AppCacheStorage::AppCacheStorage(nsILoadContextInfo* aInfo,
                                  nsIApplicationCache* aAppCache)
@@ -167,4 +168,5 @@ NS_IMETHODIMP AppCacheStorage::GetCacheIndexEntryAttrs(
   return NS_ERROR_NOT_IMPLEMENTED;
 }
 
-}  // namespace mozilla::net
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/cache2/CacheStorage.cpp b/netwerk/cache2/CacheStorage.cpp
index c1aab0749dd2..d26ceb87eb1b 100644
--- a/netwerk/cache2/CacheStorage.cpp
+++ b/netwerk/cache2/CacheStorage.cpp
@@ -19,7 +19,8 @@
 #include "nsNetUtil.h"
 #include "nsServiceManagerUtils.h"
 
-namespace mozilla::net {
+namespace mozilla {
+namespace net {
 
 NS_IMPL_ISUPPORTS(CacheStorage, nsICacheStorage)
 
@@ -250,4 +251,5 @@ nsresult CacheStorage::ChooseApplicationCache(nsIURI* aURI,
   return NS_OK;
 }
 
-}  // namespace mozilla::net
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/dns/nsHostResolver.cpp b/netwerk/dns/nsHostResolver.cpp
index b3215212764f..6147e380877c 100644
--- a/netwerk/dns/nsHostResolver.cpp
+++ b/netwerk/dns/nsHostResolver.cpp
@@ -82,7 +82,8 @@ static_assert(
 
 //----------------------------------------------------------------------------
 
-namespace mozilla::net {
+namespace mozilla {
+namespace net {
 LazyLogModule gHostResolverLog("nsHostResolver");
 #define LOG(args) \
   MOZ_LOG(mozilla::net::gHostResolverLog, mozilla::LogLevel::Debug, args)
@@ -90,7 +91,8 @@ LazyLogModule gHostResolverLog("nsHostResolver");
   MOZ_LOG(mozilla::net::gHostResolverLog, mozilla::LogLevel::Error, args)
 #define LOG_ENABLED() \
   MOZ_LOG_TEST(mozilla::net::gHostResolverLog, mozilla::LogLevel::Debug)
-}  // namespace mozilla::net
+}  // namespace net
+}  // namespace mozilla
 
 //----------------------------------------------------------------------------
 
diff --git a/netwerk/protocol/http/nsHttpChannelAuthProvider.cpp b/netwerk/protocol/http/nsHttpChannelAuthProvider.cpp
index 76d88bdfb810..ee5033e8a097 100644
--- a/netwerk/protocol/http/nsHttpChannelAuthProvider.cpp
+++ b/netwerk/protocol/http/nsHttpChannelAuthProvider.cpp
@@ -37,7 +37,8 @@
 #include "nsIProxiedChannel.h"
 #include "nsIProxyInfo.h"
 
-namespace mozilla::net {
+namespace mozilla {
+namespace net {
 
 #define SUBRESOURCE_AUTH_DIALOG_DISALLOW_ALL 0
 #define SUBRESOURCE_AUTH_DIALOG_DISALLOW_CROSS_ORIGIN 1
@@ -1663,4 +1664,5 @@ NS_IMPL_ISUPPORTS(nsHttpChannelAuthProvider, nsICancelable,
                   nsIHttpChannelAuthProvider, nsIAuthPromptCallback,
                   nsIHttpAuthenticatorCallback)
 
-}  // namespace mozilla::net
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/protocol/http/nsHttpHandler.cpp b/netwerk/protocol/http/nsHttpHandler.cpp
index edbf1289c904..f37f932d787a 100644
--- a/netwerk/protocol/http/nsHttpHandler.cpp
+++ b/netwerk/protocol/http/nsHttpHandler.cpp
@@ -132,7 +132,8 @@
 
 using mozilla::dom::Promise;
 
-namespace mozilla::net {
+namespace mozilla {
+namespace net {
 
 LazyLogModule gHttpLog("nsHttp");
 
@@ -293,7 +294,8 @@ nsHttpHandler::nsHttpHandler()
       mNextChannelId(1),
       mLastActiveTabLoadOptimizationLock(
           "nsHttpConnectionMgr::LastActiveTabLoadOptimization"),
-      mSpdyBlacklistLock("nsHttpHandler::SpdyBlacklist"),
+      mSpdyBlacklistLock(
+          "nsHttpHandler::SpdyBlacklist"),
       mThroughCaptivePortal(false) {
   LOG(("Creating nsHttpHandler [this=%p].\n", this));
 
@@ -2723,4 +2725,5 @@ nsresult nsHttpHandler::CancelTransaction(HttpTransactionShell* trans,
   return mConnMgr->CancelTransaction(trans, reason);
 }
 
-}  // namespace mozilla::net
+}  // namespace net
+}  // namespace mozilla
diff --git a/netwerk/system/netlink/NetlinkService.cpp b/netwerk/system/netlink/NetlinkService.cpp
index d803d3693a0d..fb3d0b47f287 100644
--- a/netwerk/system/netlink/NetlinkService.cpp
+++ b/netwerk/system/netlink/NetlinkService.cpp
@@ -35,7 +35,8 @@
 /* a shorter name that better explains what it does */
 #define EINTR_RETRY(x) MOZ_TEMP_FAILURE_RETRY(x)
 
-namespace mozilla::net {
+namespace mozilla {
+namespace net {
 
 // period during which to absorb subsequent network change events, in
 // milliseconds
@@ -1798,4 +1799,5 @@ void NetlinkService::GetIsLinkUp(bool* aIsUp) {
   *aIsUp = mLinkUp;
 }
 
-}  // namespace mozilla::net
+}  // namespace net
+}  // namespace mozilla
diff --git a/storage/mozStorageBindingParams.cpp b/storage/mozStorageBindingParams.cpp
index 17d91a86af99..d7ea5ad2a445 100644
--- a/storage/mozStorageBindingParams.cpp
+++ b/storage/mozStorageBindingParams.cpp
@@ -15,7 +15,8 @@
 #include "mozStorageBindingParamsArray.h"
 #include "Variant.h"
 
-namespace mozilla::storage {
+namespace mozilla {
+namespace storage {
 
 ////////////////////////////////////////////////////////////////////////////////
 //// Local Helper Objects
@@ -431,4 +432,5 @@ BindingParams::BindAdoptedBlobByIndex(uint32_t aIndex, uint8_t* aValue,
   return BindByIndex(aIndex, value);
 }
 
-}  // namespace mozilla::storage
+}  // namespace storage
+}  // namespace mozilla
diff --git a/storage/mozStorageConnection.cpp b/storage/mozStorageConnection.cpp
index 11e6c9cb384b..bd746db66ed9 100644
--- a/storage/mozStorageConnection.cpp
+++ b/storage/mozStorageConnection.cpp
@@ -70,7 +70,8 @@ mozilla::LazyLogModule gStorageLog("mozStorage");
     } while (0)
 #endif
 
-namespace mozilla::storage {
+namespace mozilla {
+namespace storage {
 
 using mozilla::dom::quota::QuotaObject;
 
@@ -2278,4 +2279,5 @@ Connection::GetQuotaObjects(QuotaObject** aDatabaseQuotaObject,
   return NS_OK;
 }
 
-}  // namespace mozilla::storage
+}  // namespace storage
+}  // namespace mozilla
diff --git a/toolkit/components/ctypes/ctypes.cpp b/toolkit/components/ctypes/ctypes.cpp
index 9b8b25b66273..baa56c94df9a 100644
--- a/toolkit/components/ctypes/ctypes.cpp
+++ b/toolkit/components/ctypes/ctypes.cpp
@@ -14,7 +14,8 @@
 #include "nsZipArchive.h"
 #include "xpc_make_class.h"
 
-namespace mozilla::ctypes {
+namespace mozilla {
+namespace ctypes {
 
 static char* UnicodeToNative(JSContext* cx, const char16_t* source,
                              size_t slen) {
@@ -97,4 +98,5 @@ Module::Call(nsIXPConnectWrappedNative* wrapper, JSContext* cx, JSObject* obj,
   return NS_OK;
 }
 
-}  // namespace mozilla::ctypes
+}  // namespace ctypes
+}  // namespace mozilla
diff --git a/toolkit/components/reflect/reflect.cpp b/toolkit/components/reflect/reflect.cpp
index c41f6bc1adb9..3688e7b75acd 100644
--- a/toolkit/components/reflect/reflect.cpp
+++ b/toolkit/components/reflect/reflect.cpp
@@ -10,7 +10,8 @@
 #include "nsNativeCharsetUtils.h"
 #include "xpc_make_class.h"
 
-namespace mozilla::reflect {
+namespace mozilla {
+namespace reflect {
 
 NS_IMPL_ISUPPORTS(Module, nsIXPCScriptable)
 
@@ -34,4 +35,5 @@ Module::Call(nsIXPConnectWrappedNative* wrapper, JSContext* cx, JSObject* obj,
   return NS_OK;
 }
 
-}  // namespace mozilla::reflect
+}  // namespace reflect
+}  // namespace mozilla
diff --git a/toolkit/components/telemetry/core/Stopwatch.cpp b/toolkit/components/telemetry/core/Stopwatch.cpp
index 598b6e944b2b..e41d8d50bc86 100644
--- a/toolkit/components/telemetry/core/Stopwatch.cpp
+++ b/toolkit/components/telemetry/core/Stopwatch.cpp
@@ -49,7 +49,8 @@ static void LogError(JSContext* aCx, const nsCString& aMessage) {
   }
 }
 
-namespace mozilla::telemetry {
+namespace mozilla {
+namespace telemetry {
 
 class Timer final {
  public:
@@ -427,4 +428,5 @@ void Stopwatch::SetTestModeEnabled(const dom::GlobalObject& aGlobal,
   Timers::Singleton().SuppressErrors() = aTesting;
 }
 
-}  // namespace mozilla::telemetry
+}  // namespace telemetry
+}  // namespace mozilla
diff --git a/toolkit/components/telemetry/core/Telemetry.cpp b/toolkit/components/telemetry/core/Telemetry.cpp
index 036375025e75..d0eea0c34094 100644
--- a/toolkit/components/telemetry/core/Telemetry.cpp
+++ b/toolkit/components/telemetry/core/Telemetry.cpp
@@ -1194,11 +1194,11 @@ static void internal_initFogotype(bool aUseTelemetry) {
     NS_WARNING("Couldn't find pingsender. Bailing on FOGotype");
     return;
   }
-#  ifdef XP_WIN
+#ifdef XP_WIN
   pingsender->Append(NS_LITERAL_STRING("pingsender.exe"));
-#  else
+#else
   pingsender->Append(NS_LITERAL_STRING("pingsender"));
-#  endif
+#endif
   nsAutoString pingsenderPath;
   rv = pingsender->GetPath(pingsenderPath);
   if (NS_FAILED(rv)) {
@@ -1986,7 +1986,8 @@ void RecordShutdownEndTimeStamp() {
 // EXTERNALLY VISIBLE FUNCTIONS in mozilla::Telemetry::
 // These are listed in Telemetry.h
 
-namespace mozilla::Telemetry {
+namespace mozilla {
+namespace Telemetry {
 
 // The external API for controlling recording state
 void SetHistogramRecordingEnabled(HistogramID aID, bool aEnabled) {
@@ -2206,7 +2207,8 @@ void RecordOrigin(mozilla::Telemetry::OriginMetricID aId,
 
 void ShutdownTelemetry() { TelemetryImpl::ShutdownTelemetry(); }
 
-}  // namespace mozilla::Telemetry
+}  // namespace Telemetry
+}  // namespace mozilla
 
 NS_IMPL_COMPONENT_FACTORY(nsITelemetry) {
   return TelemetryImpl::CreateTelemetryInstance().downcast<nsISupports>();
diff --git a/toolkit/components/telemetry/core/TelemetryCommon.cpp b/toolkit/components/telemetry/core/TelemetryCommon.cpp
index 929a72f1ed4c..c476d6fc7c5a 100644
--- a/toolkit/components/telemetry/core/TelemetryCommon.cpp
+++ b/toolkit/components/telemetry/core/TelemetryCommon.cpp
@@ -18,7 +18,9 @@
 #include "TelemetryProcessData.h"
 #include "Telemetry.h"
 
-namespace mozilla::Telemetry::Common {
+namespace mozilla {
+namespace Telemetry {
+namespace Common {
 
 bool IsExpiredVersion(const char* aExpiration) {
   MOZ_ASSERT(aExpiration);
@@ -197,4 +199,6 @@ SupportedProduct GetCurrentProduct() {
 #endif
 }
 
-}  // namespace mozilla::Telemetry::Common
+}  // namespace Common
+}  // namespace Telemetry
+}  // namespace mozilla
diff --git a/toolkit/components/telemetry/other/CombinedStacks.cpp b/toolkit/components/telemetry/other/CombinedStacks.cpp
index b767705b0653..837e7c365864 100644
--- a/toolkit/components/telemetry/other/CombinedStacks.cpp
+++ b/toolkit/components/telemetry/other/CombinedStacks.cpp
@@ -10,7 +10,8 @@
 #include "js/Array.h"  // JS::NewArrayObject
 #include "mozilla/HangAnnotations.h"
 
-namespace mozilla::Telemetry {
+namespace mozilla {
+namespace Telemetry {
 
 // The maximum number of chrome hangs stacks that we're keeping.
 const size_t kMaxChromeStacksKept = 50;
@@ -224,4 +225,5 @@ JSObject* CreateJSStackObject(JSContext* cx, const CombinedStacks& stacks) {
   return ret;
 }
 
-}  // namespace mozilla::Telemetry
+}  // namespace Telemetry
+}  // namespace mozilla
diff --git a/toolkit/components/telemetry/other/KeyedStackCapturer.cpp b/toolkit/components/telemetry/other/KeyedStackCapturer.cpp
index d71add9694ed..6e0526001078 100644
--- a/toolkit/components/telemetry/other/KeyedStackCapturer.cpp
+++ b/toolkit/components/telemetry/other/KeyedStackCapturer.cpp
@@ -57,7 +57,8 @@ bool IsKeyValid(const nsACString& aKey) {
 
 }  // anonymous namespace
 
-namespace mozilla::Telemetry {
+namespace mozilla {
+namespace Telemetry {
 
 void KeyedStackCapturer::Capture(const nsACString& aKey) {
   MutexAutoLock captureStackMutex(mStackCapturerMutex);
@@ -161,4 +162,5 @@ size_t KeyedStackCapturer::SizeOfExcludingThis(
   return n;
 }
 
-}  // namespace mozilla::Telemetry
+}  // namespace Telemetry
+}  // namespace mozilla
diff --git a/toolkit/components/telemetry/other/ProcessedStack.cpp b/toolkit/components/telemetry/other/ProcessedStack.cpp
index ce62826a05f8..6ef1b2ed588a 100644
--- a/toolkit/components/telemetry/other/ProcessedStack.cpp
+++ b/toolkit/components/telemetry/other/ProcessedStack.cpp
@@ -26,7 +26,8 @@ static bool CompareByIndex(const StackFrame& a, const StackFrame& b) {
 
 }  // namespace
 
-namespace mozilla::Telemetry {
+namespace mozilla {
+namespace Telemetry {
 
 const size_t kMaxChromeStackDepth = 50;
 
@@ -185,4 +186,5 @@ ProcessedStack BatchProcessedStackGenerator::GetStackAndModules(
 #endif
 }
 
-}  // namespace mozilla::Telemetry
+}  // namespace Telemetry
+}  // namespace mozilla
diff --git a/toolkit/components/telemetry/other/TelemetryIOInterposeObserver.cpp b/toolkit/components/telemetry/other/TelemetryIOInterposeObserver.cpp
index 5cc5f2df780f..b741fd3fe3cc 100644
--- a/toolkit/components/telemetry/other/TelemetryIOInterposeObserver.cpp
+++ b/toolkit/components/telemetry/other/TelemetryIOInterposeObserver.cpp
@@ -8,7 +8,8 @@
 #include "core/TelemetryCommon.h"
 #include "js/Array.h"  // JS::NewArrayObject
 
-namespace mozilla::Telemetry {
+namespace mozilla {
+namespace Telemetry {
 
 TelemetryIOInterposeObserver::TelemetryIOInterposeObserver(nsIFile* aXreDir)
     : mCurStage(STAGE_STARTUP) {
@@ -175,4 +176,5 @@ size_t TelemetryIOInterposeObserver::SizeOfExcludingThis(
   return size;
 }
 
-}  // namespace mozilla::Telemetry
+}  // namespace Telemetry
+}  // namespace mozilla
diff --git a/toolkit/components/url-classifier/HashStore.cpp b/toolkit/components/url-classifier/HashStore.cpp
index 523b57f3e8ba..3959615a10ee 100644
--- a/toolkit/components/url-classifier/HashStore.cpp
+++ b/toolkit/components/url-classifier/HashStore.cpp
@@ -101,7 +101,8 @@ extern mozilla::LazyLogModule gUrlClassifierDbServiceLog;
 #define LOG_ENABLED() \
   MOZ_LOG_TEST(gUrlClassifierDbServiceLog, mozilla::LogLevel::Debug)
 
-namespace mozilla::safebrowsing {
+namespace mozilla {
+namespace safebrowsing {
 
 const uint32_t STORE_MAGIC = 0x1231af3b;
 const uint32_t CURRENT_VERSION = 4;
@@ -1177,4 +1178,5 @@ ChunkSet& HashStore::SubChunks() {
   return mSubChunks;
 }
 
-}  // namespace mozilla::safebrowsing
+}  // namespace safebrowsing
+}  // namespace mozilla
diff --git a/toolkit/components/url-classifier/VariableLengthPrefixSet.cpp b/toolkit/components/url-classifier/VariableLengthPrefixSet.cpp
index 66c28ccab9d5..f7873e9b1b6c 100644
--- a/toolkit/components/url-classifier/VariableLengthPrefixSet.cpp
+++ b/toolkit/components/url-classifier/VariableLengthPrefixSet.cpp
@@ -24,7 +24,8 @@ static mozilla::LazyLogModule gUrlClassifierPrefixSetLog(
 #define LOG_ENABLED() \
   MOZ_LOG_TEST(gUrlClassifierPrefixSetLog, mozilla::LogLevel::Debug)
 
-namespace mozilla::safebrowsing {
+namespace mozilla {
+namespace safebrowsing {
 
 #define PREFIX_SIZE_FIXED 4
 
@@ -491,4 +492,5 @@ size_t VariableLengthPrefixSet::SizeOfIncludingThis(
   return n;
 }
 
-}  // namespace mozilla::safebrowsing
+}  // namespace safebrowsing
+}  // namespace mozilla
diff --git a/toolkit/xre/nsAppRunner.cpp b/toolkit/xre/nsAppRunner.cpp
index 02e138cbe60b..a478e87da098 100644
--- a/toolkit/xre/nsAppRunner.cpp
+++ b/toolkit/xre/nsAppRunner.cpp
@@ -3634,14 +3634,16 @@ bool IsWaylandDisabled() {
 }
 #endif
 
-namespace mozilla::startup {
+namespace mozilla {
+namespace startup {
 Result<nsCOMPtr<nsIFile>, nsresult> GetIncompleteStartupFile(nsIFile* aProfLD) {
   nsCOMPtr<nsIFile> crashFile;
   MOZ_TRY(aProfLD->Clone(getter_AddRefs(crashFile)));
   MOZ_TRY(crashFile->Append(FILE_STARTUP_INCOMPLETE));
   return std::move(crashFile);
 }
-}  // namespace mozilla::startup
+}  // namespace startup
+}  // namespace mozilla
 
 // Check whether the last startup attempt resulted in a crash within the
 // last 6 hours.
diff --git a/toolkit/xre/nsEmbedFunctions.cpp b/toolkit/xre/nsEmbedFunctions.cpp
index 4b97237a2082..c1c3ed091c89 100644
--- a/toolkit/xre/nsEmbedFunctions.cpp
+++ b/toolkit/xre/nsEmbedFunctions.cpp
@@ -248,9 +248,11 @@ const char* XRE_ChildProcessTypeToAnnotation(GeckoProcessType aProcessType) {
   }
 }
 
-namespace mozilla::startup {
+namespace mozilla {
+namespace startup {
 GeckoProcessType sChildProcessType = GeckoProcessType_Default;
-}  // namespace mozilla::startup
+}  // namespace startup
+}  // namespace mozilla
 
 #if defined(MOZ_WIDGET_ANDROID)
 void XRE_SetAndroidChildFds(JNIEnv* env, const XRE_AndroidChildFds& fds) {
diff --git a/tools/profiler/core/memory_hooks.cpp b/tools/profiler/core/memory_hooks.cpp
index 7121076fc8f4..3b93f09fe466 100644
--- a/tools/profiler/core/memory_hooks.cpp
+++ b/tools/profiler/core/memory_hooks.cpp
@@ -61,7 +61,8 @@ static ProfilerCounterTotal* sCounter;
 // memory hook that might try to access the value after or during deletion.
 static mozilla::FastBernoulliTrial* gBernoulli;
 
-namespace mozilla::profiler {
+namespace mozilla {
+namespace profiler {
 
 //---------------------------------------------------------------------------
 // Utilities
@@ -447,7 +448,8 @@ static void FreeCallback(void* aPtr) {
   }
 }
 
-}  // namespace mozilla::profiler
+}  // namespace profiler
+}  // namespace mozilla
 
 //---------------------------------------------------------------------------
 // malloc/free interception
@@ -554,7 +556,8 @@ void replace_init(malloc_table_t* aMallocTable, ReplaceMallocBridge** aBridge) {
 
 void profiler_replace_remove() {}
 
-namespace mozilla::profiler {
+namespace mozilla {
+namespace profiler {
 //---------------------------------------------------------------------------
 // Initialization
 //---------------------------------------------------------------------------
@@ -616,4 +619,5 @@ void disable_native_allocations() {
   }
 }
 
-}  // namespace mozilla::profiler
+}  // namespace profiler
+}  // namespace mozilla
diff --git a/widget/GfxInfoX11.cpp b/widget/GfxInfoX11.cpp
index 267afaec5475..99c615be5663 100644
--- a/widget/GfxInfoX11.cpp
+++ b/widget/GfxInfoX11.cpp
@@ -27,7 +27,8 @@
 bool fire_glxtest_process();
 #endif
 
-namespace mozilla::widget {
+namespace mozilla {
+namespace widget {
 
 #ifdef DEBUG
 NS_IMPL_ISUPPORTS_INHERITED(GfxInfo, GfxInfoBase, nsIGfxInfoDebug)
@@ -683,4 +684,5 @@ NS_IMETHODIMP GfxInfo::FireTestProcess() {
 
 #endif
 
-}  // namespace mozilla::widget
+}  // end namespace widget
+}  // end namespace mozilla
diff --git a/widget/LSBUtils.cpp b/widget/LSBUtils.cpp
index 6cd304442044..01a54ab30433 100644
--- a/widget/LSBUtils.cpp
+++ b/widget/LSBUtils.cpp
@@ -10,7 +10,9 @@
 #include "base/process_util.h"
 #include "mozilla/FileUtils.h"
 
-namespace mozilla::widget::lsb {
+namespace mozilla {
+namespace widget {
+namespace lsb {
 
 static const char* gLsbReleasePath = "/usr/bin/lsb_release";
 
@@ -64,4 +66,6 @@ bool GetLSBRelease(nsACString& aDistributor, nsACString& aDescription,
   return true;
 }
 
-}  // namespace mozilla::widget::lsb
+}  // namespace lsb
+}  // namespace widget
+}  // namespace mozilla
diff --git a/widget/ScreenManager.cpp b/widget/ScreenManager.cpp
index 7c85a0dd4d85..fc7b50e49bc4 100644
--- a/widget/ScreenManager.cpp
+++ b/widget/ScreenManager.cpp
@@ -19,7 +19,8 @@
 
 static mozilla::LazyLogModule sScreenLog("WidgetScreen");
 
-namespace mozilla::widget {
+namespace mozilla {
+namespace widget {
 
 NS_IMPL_ISUPPORTS(ScreenManager, nsIScreenManager)
 
@@ -242,4 +243,5 @@ ScreenManager::GetTotalScreenPixels(int64_t* aTotalScreenPixels) {
   return NS_OK;
 }
 
-}  // namespace mozilla::widget
+}  // namespace widget
+}  // namespace mozilla
diff --git a/widget/WindowSurfaceX11SHM.cpp b/widget/WindowSurfaceX11SHM.cpp
index 889881d22d24..425cf3b6fdfd 100644
--- a/widget/WindowSurfaceX11SHM.cpp
+++ b/widget/WindowSurfaceX11SHM.cpp
@@ -6,7 +6,8 @@
 
 #include "WindowSurfaceX11SHM.h"
 
-namespace mozilla::widget {
+namespace mozilla {
+namespace widget {
 
 WindowSurfaceX11SHM::WindowSurfaceX11SHM(Display* aDisplay, Drawable aWindow,
                                          Visual* aVisual, unsigned int aDepth) {
@@ -24,4 +25,5 @@ void WindowSurfaceX11SHM::Commit(const LayoutDeviceIntRegion& aInvalidRegion) {
   mBackImage->Put(aInvalidRegion);
 }
 
-}  // namespace mozilla::widget
+}  // namespace widget
+}  // namespace mozilla
diff --git a/widget/gtk/MediaKeysEventSourceFactory.cpp b/widget/gtk/MediaKeysEventSourceFactory.cpp
index 8784d1a1cf63..57dc7d3c4659 100644
--- a/widget/gtk/MediaKeysEventSourceFactory.cpp
+++ b/widget/gtk/MediaKeysEventSourceFactory.cpp
@@ -4,11 +4,13 @@
 
 #include "MediaKeysEventSourceFactory.h"
 
-namespace mozilla::widget {
+namespace mozilla {
+namespace widget {
 
 mozilla::dom::MediaControlKeysEventSource* CreateMediaControlKeysEventSource() {
   // TODO : will implement this in bug 1353652.
   return nullptr;
 }
 
-}  // namespace mozilla::widget
+}  // namespace widget
+}  // namespace mozilla
diff --git a/widget/gtk/mozwayland/mozwayland.c b/widget/gtk/mozwayland/mozwayland.c
index 19fc2c1b35b6..5cea1c5d1653 100644
--- a/widget/gtk/mozwayland/mozwayland.c
+++ b/widget/gtk/mozwayland/mozwayland.c
@@ -18,20 +18,20 @@ union wl_argument;
  * them explicitly visible.
  */
 #pragma GCC visibility push(default)
-const struct wl_interface wl_buffer_interface {};
-const struct wl_interface wl_callback_interface {};
-const struct wl_interface wl_data_device_interface {};
-const struct wl_interface wl_data_device_manager_interface {};
-const struct wl_interface wl_keyboard_interface {};
-const struct wl_interface wl_region_interface {};
-const struct wl_interface wl_registry_interface {};
-const struct wl_interface wl_shm_interface {};
-const struct wl_interface wl_shm_pool_interface {};
-const struct wl_interface wl_seat_interface {};
-const struct wl_interface wl_surface_interface {};
-const struct wl_interface wl_subsurface_interface {};
-const struct wl_interface wl_compositor_interface {};
-const struct wl_interface wl_subcompositor_interface {};
+const struct wl_interface wl_buffer_interface;
+const struct wl_interface wl_callback_interface;
+const struct wl_interface wl_data_device_interface;
+const struct wl_interface wl_data_device_manager_interface;
+const struct wl_interface wl_keyboard_interface;
+const struct wl_interface wl_region_interface;
+const struct wl_interface wl_registry_interface;
+const struct wl_interface wl_shm_interface;
+const struct wl_interface wl_shm_pool_interface;
+const struct wl_interface wl_seat_interface;
+const struct wl_interface wl_surface_interface;
+const struct wl_interface wl_subsurface_interface;
+const struct wl_interface wl_compositor_interface;
+const struct wl_interface wl_subcompositor_interface;
 #pragma GCC visibility pop
 
 MOZ_EXPORT void wl_event_queue_destroy(struct wl_event_queue* queue) {}
diff --git a/widget/nsBaseWidget.cpp b/widget/nsBaseWidget.cpp
index 713f85db286f..9e5a83a08679 100644
--- a/widget/nsBaseWidget.cpp
+++ b/widget/nsBaseWidget.cpp
@@ -130,7 +130,8 @@ uint64_t AutoObserverNotifier::sObserverId = 0;
 // milliseconds.
 const uint32_t kAsyncDragDropTimeout = 1000;
 
-namespace mozilla::widget {
+namespace mozilla {
+namespace widget {
 
 void IMENotification::SelectionChangeDataBase::SetWritingMode(
     const WritingMode& aWritingMode) {
@@ -141,7 +142,8 @@ WritingMode IMENotification::SelectionChangeDataBase::GetWritingMode() const {
   return WritingMode(mWritingMode);
 }
 
-}  // namespace mozilla::widget
+}  // namespace widget
+}  // namespace mozilla
 
 NS_IMPL_ISUPPORTS(nsBaseWidget, nsIWidget, nsISupportsWeakReference)
 
@@ -2242,7 +2244,8 @@ already_AddRefed<nsIBidiKeyboard> nsIWidget::CreateBidiKeyboardInner() {
 }
 #endif
 
-namespace mozilla::widget {
+namespace mozilla {
+namespace widget {
 
 const char* ToChar(InputContext::Origin aOrigin) {
   switch (aOrigin) {
@@ -3036,7 +3039,8 @@ void IMENotification::TextChangeDataBase::Test() {
 
 #endif  // #ifdef DEBUG
 
-}  // namespace mozilla::widget
+}  // namespace widget
+}  // namespace mozilla
 
 #ifdef DEBUG
 //////////////////////////////////////////////////////////////