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

Source/core/page/ImageBitmap.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef ImageBitmap_h
 #define ImageBitmap_h
 
 #include "bindings/v8/ScriptWrappable.h"
 #include "core/dom/ScriptExecutionContext.h"
 #include "core/platform/graphics/BitmapImage.h"
 #include "core/platform/graphics/ImageBuffer.h"
 #include "core/platform/graphics/IntRect.h"
 #include "wtf/PassRefPtr.h"
 #include "wtf/RefCounted.h"
 
+class SkImage;
+
 namespace WebCore {
 
 class HTMLCanvasElement;
 class HTMLImageElement;
 class HTMLVideoElement;
 class ImageData;
 class ImageBitmapCallback;
 
 class ImageBitmap : public RefCounted<ImageBitmap>, public ScriptWrappable {
 
 public:
     static PassRefPtr<ImageBitmap> create(HTMLImageElement*, IntRect);
     static PassRefPtr<ImageBitmap> create(HTMLVideoElement*, IntRect);
     static PassRefPtr<ImageBitmap> create(HTMLCanvasElement*, IntRect);
     static PassRefPtr<ImageBitmap> create(ImageData*, IntRect);
     static PassRefPtr<ImageBitmap> create(ImageBitmap*, IntRect);
 
-    BitmapImage* bitmapImage() const { return m_bitmap.get(); }
+    PassRefPtr<Image> bitmapImage() const { return m_bitmap; }
+    SkImage* canvasImage() const { return m_canvasImage; }
 
-    int bitmapWidth() const { return m_bitmap->width(); }
-    int bitmapHeight() const { return m_bitmap->height(); }
-    IntSize bitmapSize() const { return m_bitmap->size(); }
+    int bitmapWidth() const { return m_bitmapSize.width(); }
+    int bitmapHeight() const { return m_bitmapSize.height(); }
+    IntSize bitmapSize() const { return m_bitmapSize; }
     IntPoint bitmapOffset() const { return m_bitmapOffset; }
 
-    int width() const { return m_size.width(); }
-    int height() const { return m_size.height(); }
-    IntSize size() const { return m_size; }
+    int width() const { return m_cropRect.width(); }
+    int height() const { return m_cropRect.height(); }
+    IntSize size() const { return m_cropRect.size(); }
+    IntRect cropRect() const { return m_cropRect; }
 
     ~ImageBitmap() { };
 
 private:
     ImageBitmap(HTMLImageElement*, IntRect);
     ImageBitmap(HTMLVideoElement*, IntRect);
     ImageBitmap(HTMLCanvasElement*, IntRect);
     ImageBitmap(ImageData*, IntRect);
     ImageBitmap(ImageBitmap*, IntRect);
 
-    RefPtr<BitmapImage> m_bitmap;
+    RefPtr<Image> m_bitmap;
     OwnPtr<ImageBuffer> m_buffer;
-
+    SkImage* m_canvasImage;

[Justin Novosad, 2013/07/22 15:35:41]

We should no use SkImage directly.  Could we have a platform-specific subclass
of BitmapImage that encapsulates an SkImage?

     IntPoint m_bitmapOffset; // offset applied to the image when it is drawn to the context
-    IntSize m_size; // user defined size of the ImageBitmap
+    IntSize m_bitmapSize; // actual size of the BitmapImage
+    IntRect m_cropRect; // user defined size of the ImageBitmap
 };
 
 } // namespace WebCore
 
 #endif // ImageBitmap_h