Bug 1722322 - Implement LargestContentfulPaint r=emilio

Spec: https://w3c.github.io/largest-contentful-paint

Differential Revision: https://phabricator.services.mozilla.com/D151079

layout/svg/SVGImageFrame.cpp

@@ -28,6 +28,7 @@
 #include "mozilla/SVGUtils.h"
 #include "mozilla/dom/MutationEventBinding.h"
 #include "mozilla/dom/SVGImageElement.h"
+#include "mozilla/dom/LargestContentfulPaint.h"
 #include "nsIReflowCallback.h"
 
 using namespace mozilla::dom;
@@ -391,6 +392,12 @@ void SVGImageFrame::PaintSVG(gfxContext& aContext, const gfxMatrix& aTransform,
       LayoutDeviceSize devPxSize(width, height);
       nsRect destRect(nsPoint(), LayoutDevicePixel::ToAppUnits(
                                      devPxSize, appUnitsPerDevPx));
+      nsCOMPtr<imgIRequest> currentRequest = GetCurrentRequest();
+      if (currentRequest) {
+        LCPHelpers::FinalizeLCPEntryForImage(
+            GetContent()->AsElement(),
+            static_cast<imgRequestProxy*>(currentRequest.get()), destRect);
+      }
 
       // Note: Can't use DrawSingleUnscaledImage for the TYPE_VECTOR case.
       // That method needs our image to have a fixed native width & height,
@@ -467,14 +474,7 @@ bool SVGImageFrame::CreateWebRenderCommands(
 
   // try to setup the image
   if (!mImageContainer) {
-    nsCOMPtr<imgIRequest> currentRequest;
-    nsCOMPtr<nsIImageLoadingContent> imageLoader =
-        do_QueryInterface(GetContent());
-    if (imageLoader) {
-      imageLoader->GetRequest(nsIImageLoadingContent::CURRENT_REQUEST,
-                              getter_AddRefs(currentRequest));
-    }
-
+    nsCOMPtr<imgIRequest> currentRequest = GetCurrentRequest();
     if (currentRequest) {
       currentRequest->GetImage(getter_AddRefs(mImageContainer));
     }
@@ -633,6 +633,14 @@ bool SVGImageFrame::CreateWebRenderCommands(
       mImageContainer, this, destRect, clipRect, aSc, flags, svgContext,
       region);
 
+  if (nsCOMPtr<imgIRequest> currentRequest = GetCurrentRequest()) {
+    LCPHelpers::FinalizeLCPEntryForImage(
+        GetContent()->AsElement(),
+        static_cast<imgRequestProxy*>(currentRequest.get()),
+        LayoutDeviceRect::ToAppUnits(destRect, appUnitsPerDevPx) -
+            toReferenceFrame);
+  }
+
   RefPtr<image::WebRenderImageProvider> provider;
   ImgDrawResult drawResult = mImageContainer->GetImageProvider(
       aManager->LayerManager(), decodeSize, svgContext, region, flags,
@@ -783,6 +791,17 @@ bool SVGImageFrame::ReflowFinished() {
 
 void SVGImageFrame::ReflowCallbackCanceled() { mReflowCallbackPosted = false; }
 
+already_AddRefed<imgIRequest> SVGImageFrame::GetCurrentRequest() const {
+  nsCOMPtr<imgIRequest> request;
+  nsCOMPtr<nsIImageLoadingContent> imageLoader =
+      do_QueryInterface(GetContent());
+  if (imageLoader) {
+    imageLoader->GetRequest(nsIImageLoadingContent::CURRENT_REQUEST,
+                            getter_AddRefs(request));
+  }
+  return request.forget();
+}
+
 bool SVGImageFrame::IgnoreHitTest() const {
   switch (Style()->PointerEvents()) {
     case StylePointerEvents::None: