Use SkImage as a backing store for copying 2d Contexts to ImageBitmaps.

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 25 matching lines @@
 #include "core/platform/graphics/IntSize.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;
+class SkSurface;
 
 namespace WebKit { class WebLayer; }
 
 namespace WebCore {
 
 class Canvas2DLayerBridge;
 class Image;
 class ImageData;
 class IntPoint;
 class IntRect;
@@ skipping 41 matching lines @@
     static PassOwnPtr<ImageBuffer> createCompatibleBuffer(const IntSize&, float resolutionScale, const GraphicsContext*, bool hasAlpha);
 
     ~ImageBuffer();
 
     // The actual resolution of the backing store
     const IntSize& internalSize() const { return m_size; }
     const IntSize& logicalSize() const { return m_logicalSize; }
 
     GraphicsContext* context() const;
 
+    PassRefPtr<Image> imageSnapshot() const;
     PassRefPtr<Image> copyImage(BackingStoreCopy = CopyBackingStore, ScaleBehavior = Scaled) const;
     // Give hints on the faster copyImage Mode, return DontCopyBackingStore if it supports the DontCopyBackingStore behavior
     // or return CopyBackingStore if it doesn't.
     static BackingStoreCopy fastCopyImageMode();
 
     enum CoordinateSystem { LogicalCoordinateSystem, BackingStoreCoordinateSystem };
 
     PassRefPtr<Uint8ClampedArray> getUnmultipliedImageData(const IntRect&, CoordinateSystem = LogicalCoordinateSystem) const;
     PassRefPtr<Uint8ClampedArray> getPremultipliedImageData(const IntRect&, CoordinateSystem = LogicalCoordinateSystem) const;
 
     void putByteArray(Multiply multiplied, Uint8ClampedArray*, const IntSize& sourceSize, const IntRect& sourceRect, const IntPoint& destPoint, CoordinateSystem = LogicalCoordinateSystem);
 
     void convertToLuminanceMask();
 
     String toDataURL(const String& mimeType, const double* quality = 0, CoordinateSystem = LogicalCoordinateSystem) const;
     AffineTransform baseTransform() const { return AffineTransform(); }
     void transformColorSpace(ColorSpace srcColorSpace, ColorSpace dstColorSpace);
     static const Vector<uint8_t>& getLinearRgbLUT();
     static const Vector<uint8_t>& getDeviceRgbLUT();
     WebKit::WebLayer* platformLayer() const;
 
     // FIXME: current implementations of this method have the restriction that they only work
     // with textures that are RGB or RGBA format, UNSIGNED_BYTE type and level 0, as specified in
     // Extensions3D::canUseCopyTextureCHROMIUM().
     bool copyToPlatformTexture(GraphicsContext3D&, Platform3DObject, GC3Denum, GC3Denum, GC3Dint, bool, bool);
 
 private:
     bool isValid() const;
+    void createAcceleratedCanvas(const IntSize&, OwnPtr<Canvas2DLayerBridge>*, OpacityMode);
+    void createNonPlatformCanvas(const IntSize&);
 
     void draw(GraphicsContext*, const FloatRect&, const FloatRect& = FloatRect(0, 0, -1, -1), CompositeOperator = CompositeSourceOver, BlendMode = BlendModeNormal, bool useLowQualityScale = false);
     void drawPattern(GraphicsContext*, const FloatRect&, const FloatSize&, const FloatPoint&, CompositeOperator, const FloatRect&, BlendMode);
 
     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<SkSurface> m_surface;
     OwnPtr<GraphicsContext> m_context;
     OwnPtr<Canvas2DLayerBridge> 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