Remove duplication of encoded image data

third_party/WebKit/Source/platform/graphics/Image.h

Index: third_party/WebKit/Source/platform/graphics/Image.h
diff --git a/third_party/WebKit/Source/platform/graphics/Image.h b/third_party/WebKit/Source/platform/graphics/Image.h
index 841a2ea4ea92d73524c02e32082db48001097da1..248f7e74d5709460434dd0e5366764d7947f4938 100644
--- a/third_party/WebKit/Source/platform/graphics/Image.h
+++ b/third_party/WebKit/Source/platform/graphics/Image.h
@@ -28,6 +28,7 @@
 #define Image_h
 
 #include "platform/PlatformExport.h"
+#include "platform/SharedBuffer.h"
 #include "platform/geometry/IntRect.h"
 #include "platform/graphics/Color.h"
 #include "platform/graphics/GraphicsTypes.h"
@@ -54,7 +55,6 @@ class FloatRect;
 class FloatSize;
 class GraphicsContext;
 class Length;
-class SharedBuffer;
 class Image;
 
 class PLATFORM_EXPORT Image : public RefCounted<Image> {
@@ -108,7 +108,7 @@ public:
 
     virtual void destroyDecodedData() = 0;
 
-    SharedBuffer* data() { return m_encodedImageData.get(); }
+    virtual PassRefPtr<SharedBuffer> data() { return m_encodedImageData; }

[haraken, 2016/06/23 01:26:41]

Is ScriptStreamer the only reason you want to change the return type to
PassRefPtr? If so, I'd prefer just keeping the old code as is, because it is
important to make sure that Image is the *only* owner of m_encodedImageData. If
the ownership is passed to other callers, we may not be able to release the
underlying SharedBuffer when resetEncodedImageData gets called.

[hajimehoshi, 2016/06/23 09:23:13]

This change is needed since the child class BitmapImage requires this change:
After this CL, a BitmapImage might return a SharedBuffer which is not owned by a
BitmapImage.

 
     // Animation begins whenever someone draws the image, so startAnimation() is not normally called.
     // It will automatically pause once all observers no longer want to render the image anywhere.
@@ -171,6 +171,10 @@ protected:
         SkXfermode::Mode, const FloatSize& repeatSpacing);
     void drawTiled(GraphicsContext&, const FloatRect& dstRect, const FloatRect& srcRect, const FloatSize& tileScaleFactor, TileRule hRule, TileRule vRule, SkXfermode::Mode);
 
+    // Releases m_encodedImageData when the subclass can have encoded image data
+    // in another way.
+    void resetEncodedImageData() { m_encodedImageData.release(); }
+
 private:
     RefPtr<SharedBuffer> m_encodedImageData;
     // TODO(Oilpan): consider having Image on the Oilpan heap and