Synchronize commits at end of JS task

third_party/WebKit/Source/core/html/canvas/CanvasRenderingContext.cpp

 /*
  * Copyright (C) 2009 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 147 matching lines @@
     m_canvas = nullptr;
   }
   if (offscreenCanvas()) {
     offscreenCanvas()->detachContext();
     m_offscreenCanvas = nullptr;
   }
 }
 
 void CanvasRenderingContext::didDraw(const SkIRect& dirtyRect) {
   canvas()->didDraw(SkRect::Make(dirtyRect));
+  needsFinalizeFrame();
+}
+
+void CanvasRenderingContext::needsFinalizeFrame() {
   if (!m_finalizeFrameScheduled) {
     m_finalizeFrameScheduled = true;
     Platform::current()->currentThread()->addTaskObserver(this);
   }
 }
 
 void CanvasRenderingContext::didProcessTask() {
   Platform::current()->currentThread()->removeTaskObserver(this);
   m_finalizeFrameScheduled = false;
 
   // The end of a script task that drew content to the canvas is the point
   // at which the current frame may be considered complete.
   if (canvas())
     canvas()->finalizeFrame();
+  if (offscreenCanvas())
+    offscreenCanvas()->finalizeFrame();
   finalizeFrame();
 }
 
 CanvasRenderingContext::ContextType CanvasRenderingContext::contextTypeFromId(
     const String& id) {
   if (id == "2d")
     return Context2d;
   if (id == "experimental-webgl")
     return ContextExperimentalWebgl;
   if (id == "webgl")
@@ skipping 43 matching lines @@
   }
   return taintOrigin;
 }
 
 DEFINE_TRACE(CanvasRenderingContext) {
   visitor->trace(m_canvas);
   visitor->trace(m_offscreenCanvas);
 }
 
 }  // namespace blink