Refactoring ImageBuffer to decouple it from Canvas2DLayerBridge

Source/core/html/HTMLCanvasElement.h

 /*
  * Copyright (C) 2004, 2006, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alp Toker <alp@atoker.com>
  * 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 27 matching lines @@
 namespace WebCore {
 
 class CanvasContextAttributes;
 class CanvasRenderingContext;
 class GraphicsContext;
 class GraphicsContextStateSaver;
 class HTMLCanvasElement;
 class Image;
 class ImageData;
 class ImageBuffer;
+class ImageBufferSurface;
 class IntSize;
 
 class CanvasObserver {
 public:
     virtual ~CanvasObserver() { }
 
     virtual void canvasChanged(HTMLCanvasElement*, const FloatRect& changedRect) = 0;
     virtual void canvasResized(HTMLCanvasElement*) = 0;
     virtual void canvasDestroyed(HTMLCanvasElement*) = 0;
 };
@@ skipping 12 matching lines @@
 
     const IntSize& size() const { return m_size; }
 
     void setWidth(int);
     void setHeight(int);
     void setAccelerationDisabled(bool accelerationDisabled) { m_accelerationDisabled = accelerationDisabled; }
     bool accelerationDisabled() const { return m_accelerationDisabled; }
 
     void setSize(const IntSize& newSize)
     {
-        if (newSize == size() && m_deviceScaleFactor == 1)
+        if (newSize == size())
             return;
         m_ignoreReset = true;
         setWidth(newSize.width());
         setHeight(newSize.height());
         m_ignoreReset = false;
         reset();
     }
 
     CanvasRenderingContext* getContext(const String&, CanvasContextAttributes* attributes = 0);
 
@@ skipping 24 matching lines @@
     bool originClean() const { return m_originClean; }
 
     AffineTransform baseTransform() const;
 
     bool is3D() const;
 
     bool hasImageBuffer() const { return m_imageBuffer.get(); }
 
     bool shouldAccelerate(const IntSize&) const;
 
-    float deviceScaleFactor() const { return m_deviceScaleFactor; }
-
     InsertionNotificationRequest insertedInto(ContainerNode*) OVERRIDE;
 
 private:
     explicit HTMLCanvasElement(Document&);
 
     virtual void parseAttribute(const QualifiedName&, const AtomicString&) OVERRIDE;
     virtual RenderObject* createRenderer(RenderStyle*);
     virtual bool areAuthorShadowsAllowed() const OVERRIDE { return false; }
 
     void reset();
 
+    PassOwnPtr<ImageBufferSurface> createImageBufferSurface(const IntSize& deviceSize, int* msaaSampleCount);
     void createImageBuffer();
     void clearImageBuffer();
 
     void setSurfaceSize(const IntSize&);
-    IntSize convertLogicalToDevice(const IntSize&) const;
 
     bool paintsIntoCanvasBuffer() const;
 
     void setExternallyAllocatedMemory(intptr_t);
 
     HashSet<CanvasObserver*> m_observers;
 
     IntSize m_size;
 
     OwnPtr<CanvasRenderingContext> m_context;
 
     bool m_rendererIsCanvas;
 
     bool m_ignoreReset;
     bool m_accelerationDisabled;
     FloatRect m_dirtyRect;
 
     intptr_t m_externallyAllocatedMemory;
 
-    float m_deviceScaleFactor; // FIXME: This is always 1 and should probable be deleted
     bool m_originClean;
 
     // It prevents HTMLCanvasElement::buffer() from continuously re-attempting to allocate an imageBuffer
     // after the first attempt failed.
     mutable bool m_didFailToCreateImageBuffer;
     mutable bool m_didClearImageBuffer;
     OwnPtr<ImageBuffer> m_imageBuffer;
     mutable OwnPtr<GraphicsContextStateSaver> m_contextStateSaver;
 
     mutable RefPtr<Image> m_presentedImage;
     mutable RefPtr<Image> m_copiedImage; // FIXME: This is temporary for platforms that have to copy the image buffer to render (and for CSSCanvasValue).
 };
 
 DEFINE_NODE_TYPE_CASTS(HTMLCanvasElement, hasTagName(HTMLNames::canvasTag));
 
 } //namespace
 
 #endif