Add a usingGPUProcess property to nsIGfxInfo. (bug 1317441 part 1, r=mattwoodrow)

widget/GfxInfoBase.cpp

@@ -30,6 +30,7 @@
 #include "mozilla/Preferences.h"
 #include "mozilla/dom/ContentChild.h"
 #include "mozilla/gfx/2D.h"
+#include "mozilla/gfx/GPUProcessManager.h"
 #include "mozilla/gfx/Logging.h"
 #include "MediaPrefs.h"
 #include "gfxPrefs.h"
@@ -1427,6 +1428,19 @@ GfxInfoBase::GetContentBackend(nsAString & aContentBackend)
   return NS_OK;
 }
 
+NS_IMETHODIMP
+GfxInfoBase::GetUsingGPUProcess(bool *aOutValue)
+{
+  GPUProcessManager* gpu = GPUProcessManager::Get();
+  if (!gpu) {
+    // Not supported in content processes.
+    return NS_ERROR_FAILURE;
+  }
+
+  *aOutValue = !!gpu->GetGPUChild();
+  return NS_OK;
+}
+
 GfxInfoCollectorBase::GfxInfoCollectorBase()
 {
   GfxInfoBase::AddCollector(this);

widget/GfxInfoBase.h

@@ -59,6 +59,7 @@ public:
   NS_IMETHOD GetFeatureLog(JSContext*, JS::MutableHandle<JS::Value>) override;
   NS_IMETHOD GetActiveCrashGuards(JSContext*, JS::MutableHandle<JS::Value>) override;
   NS_IMETHOD GetContentBackend(nsAString & aContentBackend) override;
+  NS_IMETHOD GetUsingGPUProcess(bool *aOutValue) override;
 
   // Initialization function. If you override this, you must call this class's
   // version of Init first.

widget/nsIGfxInfo.idl

@@ -15,6 +15,7 @@ interface nsIGfxInfo : nsISupports
    */
   readonly attribute boolean D2DEnabled;
   readonly attribute boolean DWriteEnabled;
+  readonly attribute boolean usingGPUProcess;
   readonly attribute DOMString DWriteVersion;
   readonly attribute DOMString cleartypeParameters;