Refactoring source image usage in CanvasRenderingContext2D

Source/core/html/HTMLImageElement.h

Index: Source/core/html/HTMLImageElement.h
diff --git a/Source/core/html/HTMLImageElement.h b/Source/core/html/HTMLImageElement.h
index 3722c30c26b5613deb6cb779550ad78e617038cb..9df604e3cd90b5c190b57ed80a9a14344484abca 100644
--- a/Source/core/html/HTMLImageElement.h
+++ b/Source/core/html/HTMLImageElement.h
@@ -26,6 +26,7 @@
 
 #include "core/html/HTMLElement.h"
 #include "core/html/HTMLImageLoader.h"
+#include "core/html/canvas/CanvasImageSource.h"
 #include "platform/graphics/GraphicsTypes.h"
 #include "wtf/WeakPtr.h"
 
@@ -33,7 +34,7 @@ namespace WebCore {
 
 class HTMLFormElement;
 
-class HTMLImageElement FINAL : public HTMLElement {
+class HTMLImageElement FINAL : public HTMLElement, public CanvasImageSource {
 public:
     static PassRefPtr<HTMLImageElement> create(Document&);
     static PassRefPtr<HTMLImageElement> create(Document&, HTMLFormElement*);
@@ -84,6 +85,12 @@ public:
     virtual HTMLFormElement* formOwner() const OVERRIDE;
     void formRemovedFromTree(const Node* formRoot);
 
+    // CanvasImageSourceImplementations
+    virtual PassRefPtr<Image> getSourceImageForCanvas(HTMLCanvasElement*, ExceptionState&, CanvasImageSourceUsage, bool* isVolatile) const;
+    virtual bool wouldTaintOrigin(CanvasRenderingContext* destination) const OVERRIDE;
+    virtual FloatSize sourceSize() const OVERRIDE;
+    virtual FloatSize defaultDestinationSize() const OVERRIDE;
+
 protected:
     explicit HTMLImageElement(Document&, HTMLFormElement* = 0);