Implementing promise-based commit for driving OffscreenCanvas animations

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 100 matching lines @@
   // HTMLCanvasElement and CanvasRenderingContext have a circular reference.
   // When the pair is no longer reachable, their destruction order is non-
   // deterministic, so the first of the two to be destroyed needs to notify
   // the other in order to break the circular reference.  This is to avoid
   // an error when CanvasRenderingContext2D::didProcessTask() is invoked
   // after the HTMLCanvasElement is destroyed.
   if (canvas()) {
     canvas()->detachContext();
     m_canvas = nullptr;
   }
+  if (offscreenCanvas()) {
+    offscreenCanvas()->detachContext();
+    m_offscreenCanvas = nullptr;
+  }
 }
 
 CanvasRenderingContext::ContextType CanvasRenderingContext::contextTypeFromId(
     const String& id) {
   if (id == "2d")
     return Context2d;
   if (id == "experimental-webgl")
     return ContextExperimentalWebgl;
   if (id == "webgl")
     return ContextWebgl;
@@ skipping 42 matching lines @@
   }
   return taintOrigin;
 }
 
 DEFINE_TRACE(CanvasRenderingContext) {
   visitor->trace(m_canvas);
   visitor->trace(m_offscreenCanvas);
 }
 
 }  // namespace blink