Fixing Canvas2DLayerBridge to handle lost graphics contexts

Source/core/testing/Internals.cpp

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  * Copyright (C) 2013 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.
@@ skipping 82 matching lines @@
 #include "core/page/FrameView.h"
 #include "core/page/Page.h"
 #include "core/page/PrintContext.h"
 #include "core/page/Settings.h"
 #include "core/page/animation/AnimationController.h"
 #include "core/page/scrolling/ScrollingCoordinator.h"
 #include "core/platform/ColorChooser.h"
 #include "core/platform/Cursor.h"
 #include "core/platform/Language.h"
 #include "core/platform/graphics/IntRect.h"
+#include "core/platform/graphics/gpu/SharedGraphicsContext3D.h"
 #include "core/rendering/RenderMenuList.h"
 #include "core/rendering/RenderObject.h"
 #include "core/rendering/RenderTreeAsText.h"
 #include "core/rendering/RenderView.h"
 #include "core/workers/WorkerThread.h"
 #include "weborigin/SchemeRegistry.h"
 #include "wtf/dtoa.h"
 #include "wtf/text/StringBuffer.h"
 
 #include "core/page/PagePopupController.h"
@@ skipping 1934 matching lines @@
     HTMLSelectElement* select = toHTMLSelectElement(node);
 
     RenderObject* renderer = select->renderer();
     if (!renderer->isMenuList())
         return false;
 
     RenderMenuList* menuList = toRenderMenuList(renderer);
     return menuList->popupIsVisible();
 }
 
+bool Internals::loseSharedGraphicsContext3D()
+{
+    RefPtr<GraphicsContext3D> sharedContext = SharedGraphicsContext3D::get();
+    if (!sharedContext)
+        return false;
+    sharedContext->getExtensions()->loseContextCHROMIUM(Extensions3D::GUILTY_CONTEXT_RESET_ARB, Extensions3D::INNOCENT_CONTEXT_RESET_ARB);
+    // To prevent tests that call loseSharedGraphicsContext3D from being
+    // flaky, we call finish so that the context is guaranteed to be lost
+    // synchronously (i.e. before returning).
+    sharedContext->finish();
+    return true;
 }
+
+}