Change Canvas2DLayerBridge to stay alive until last mailbox is returned.

Source/core/platform/graphics/ImageBuffer.h

 /*
  * Copyright (C) 2006 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Torch Mobile (Beijing) Co. Ltd. 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 16 matching lines @@
 
 #ifndef ImageBuffer_h
 #define ImageBuffer_h
 
 #include "core/platform/graphics/ColorSpace.h"
 #include "core/platform/graphics/FloatRect.h"
 #include "core/platform/graphics/GraphicsContext.h"
 #include "core/platform/graphics/GraphicsTypes.h"
 #include "core/platform/graphics/GraphicsTypes3D.h"
 #include "core/platform/graphics/IntSize.h"
+#include "core/platform/graphics/chromium/Canvas2DLayerBridge.h"
 #include "core/platform/graphics/transforms/AffineTransform.h"
 #include "wtf/Forward.h"
 #include "wtf/OwnPtr.h"
 #include "wtf/PassOwnPtr.h"
 #include "wtf/PassRefPtr.h"
 #include "wtf/Uint8ClampedArray.h"
 #include "wtf/Vector.h"
 
 class SkCanvas;
 
 namespace WebKit { class WebLayer; }
 
 namespace WebCore {
 
-class Canvas2DLayerBridge;
 class Image;
 class ImageData;
 class IntPoint;
 class IntRect;
 class GraphicsContext3D;
 
 enum Multiply {
     Premultiplied,
     Unmultiplied
 };
@@ skipping 77 matching lines @@
     friend class GraphicsContext;
     friend class GeneratedImage;
     friend class CrossfadeGeneratedImage;
     friend class GeneratorGeneratedImage;
 
     IntSize m_size;
     IntSize m_logicalSize;
     float m_resolutionScale;
     OwnPtr<SkCanvas> m_canvas;
     OwnPtr<GraphicsContext> m_context;
-    OwnPtr<Canvas2DLayerBridge> m_layerBridge;
+    Canvas2DLayerBridgePtr m_layerBridge;
 
     // This constructor will place its success into the given out-variable
     // so that create() knows when it should return failure.
     ImageBuffer(const IntSize&, float resolutionScale, RenderingMode, OpacityMode, bool& success);
     ImageBuffer(const IntSize&, float resolutionScale, const GraphicsContext*, bool hasAlpha, bool& success);
 };
 
 String ImageDataToDataURL(const ImageData&, const String& mimeType, const double* quality);
 
 } // namespace WebCore
 
 #endif // ImageBuffer_h