Refactoring ImageBuffer to decouple it from Canvas2DLayerBridge

Source/core/platform/graphics/Canvas2DImageBufferSurface.h

Index: Source/core/platform/graphics/Canvas2DImageBufferSurface.h
diff --git a/Source/core/html/parser/HTMLSrcsetParser.h b/Source/core/platform/graphics/Canvas2DImageBufferSurface.h
similarity index 55%
copy from Source/core/html/parser/HTMLSrcsetParser.h
copy to Source/core/platform/graphics/Canvas2DImageBufferSurface.h
index 8964ffbcd5f61ee309ab67d2e4fe83855e89c736..406ba591d1f83431a6e0e9c24bff378e05812494 100644
--- a/Source/core/html/parser/HTMLSrcsetParser.h
+++ b/Source/core/platform/graphics/Canvas2DImageBufferSurface.h
@@ -28,52 +28,38 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef HTMLSrcsetParser_h
-#define HTMLSrcsetParser_h
+#ifndef Canvas2DImageBufferSurface_h
+#define Canvas2DImageBufferSurface_h
 
-#include "wtf/text/WTFString.h"
+#include "core/platform/graphics/Canvas2DLayerBridge.h"
+#include "platform/graphics/ImageBufferSurface.h"
 
 namespace WebCore {
 
-class ImageCandidate {
+// This shim necessary because ImageBufferSurfaces are not allowed to be RefCounted
+class Canvas2DImageBufferSurface : public ImageBufferSurface {
 public:
-    ImageCandidate()
-        : m_scaleFactor(1.0)
+    Canvas2DImageBufferSurface(const IntSize& size, OpacityMode opacityMode, float resolutionScale, int msaaSampleCount)
+        : ImageBufferSurface(size, opacityMode, resolutionScale)
+        , m_layerBridge(Canvas2DLayerBridge::create(size, opacityMode, msaaSampleCount))
     {
+        clear();
     }
 
-    ImageCandidate(const String& source, unsigned start, unsigned length, float scaleFactor)
-        : m_string(source.createView(start, length))
-        , m_scaleFactor(scaleFactor)
-    {
-    }
+    virtual ~Canvas2DImageBufferSurface() { m_layerBridge->destroy(); }
 
-    String toString() const
-    {
-        return m_string.toString();
-    }
-
-    inline float scaleFactor() const
-    {
-        return m_scaleFactor;
-    }
-
-    inline bool isEmpty() const
-    {
-        return m_string.isEmpty();
-    }
+    // ImageBufferSurface implementation
+    virtual void aboutToUse() OVERRIDE { m_layerBridge->aboutToUse(); }
+    virtual SkCanvas* canvas() const OVERRIDE { return m_layerBridge->canvas(); }
+    virtual bool isValid() const OVERRIDE { return m_layerBridge && m_layerBridge->isValid(); }
+    virtual blink::WebLayer* layer() const OVERRIDE { return m_layerBridge->layer(); }
+    virtual Platform3DObject getBackingTexture() const OVERRIDE { return m_layerBridge->getBackingTexture(); }
+    virtual bool isAccelerated() const { return m_layerBridge->isAccelerated(); }
 
 private:
-    StringView m_string;
-    float m_scaleFactor;
+    RefPtr<Canvas2DLayerBridge> m_layerBridge;
 };
 
-ImageCandidate bestFitSourceForSrcsetAttribute(float deviceScaleFactor, const String& srcsetAttribute);
-
-ImageCandidate bestFitSourceForImageAttributes(float deviceScaleFactor, const String& srcAttribute, const String& srcsetAttribute);
-
-String bestFitSourceForImageAttributes(float deviceScaleFactor, const String& srcAttribute, ImageCandidate& srcsetImageCandidate);
-
 }
 
 #endif