Refactoring source image usage in CanvasRenderingContext2D

Source/core/html/HTMLVideoElement.h

 /*
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 #ifndef HTMLVideoElement_h
 #define HTMLVideoElement_h
 
 #include "core/html/HTMLMediaElement.h"
+#include "core/html/canvas/CanvasImageSource.h"
 
 namespace blink {
 class WebGraphicsContext3D;
 }
 
 namespace WebCore {
 
 class ExceptionState;
 class HTMLImageLoader;
 
-class HTMLVideoElement FINAL : public HTMLMediaElement {
+class HTMLVideoElement FINAL : public HTMLMediaElement, public CanvasImageSource {
 public:
     static PassRefPtr<HTMLVideoElement> create(Document&);
 
     unsigned videoWidth() const;
     unsigned videoHeight() const;
 
     // Statistics
     unsigned webkitDecodedFrameCount() const;
     unsigned webkitDroppedFrameCount() const;
 
     // Used by canvas to gain raw pixel access
-    void paintCurrentFrameInContext(GraphicsContext*, const IntRect&);
+    void paintCurrentFrameInContext(GraphicsContext*, const IntRect&) const;
 
     // Used by WebGL to do GPU-GPU textures copy if possible.
     // See more details at MediaPlayer::copyVideoTextureToPlatformTexture() defined in Source/WebCore/platform/graphics/MediaPlayer.h.
     bool copyVideoTextureToPlatformTexture(blink::WebGraphicsContext3D*, Platform3DObject texture, GC3Dint level, GC3Denum type, GC3Denum internalFormat, bool premultiplyAlpha, bool flipY);
 
     bool shouldDisplayPosterImage() const { return displayMode() == Poster || displayMode() == PosterWaitingForVideo; }
 
     KURL posterImageURL() const;
 
     // FIXME: Remove this when WebMediaPlayerClientImpl::loadInternal does not depend on it.
     virtual KURL mediaPlayerPosterURL() OVERRIDE;
 
+    // CanvasImageSource implementation
+    virtual PassRefPtr<Image> getSourceImageForCanvas(SourceImageMode, SourceImageStatus*) const OVERRIDE;
+    virtual bool isVideoElement() const OVERRIDE { return true; }
+    virtual bool wouldTaintOrigin(SecurityOrigin*) const OVERRIDE;
+    virtual FloatSize sourceSize() const OVERRIDE;
+
 private:
     HTMLVideoElement(Document&);
 
     virtual bool rendererIsNeeded(const RenderStyle&) OVERRIDE;
     virtual RenderObject* createRenderer(RenderStyle*) OVERRIDE;
     virtual void attach(const AttachContext& = AttachContext()) OVERRIDE;
     virtual void parseAttribute(const QualifiedName&, const AtomicString&) OVERRIDE;
     virtual bool isPresentationAttribute(const QualifiedName&) const OVERRIDE;
     virtual void collectStyleForPresentationAttribute(const QualifiedName&, const AtomicString&, MutableStylePropertySet*) OVERRIDE;
     virtual bool isVideo() const OVERRIDE { return true; }
     virtual bool hasVideo() const OVERRIDE { return player() && player()->hasVideo(); }
     virtual bool isURLAttribute(const Attribute&) const OVERRIDE;
     virtual const AtomicString imageSourceURL() const OVERRIDE;
 
     bool hasAvailableVideoFrame() const;
     virtual void updateDisplayState() OVERRIDE;
     virtual void didMoveToNewDocument(Document& oldDocument) OVERRIDE;
     virtual void setDisplayMode(DisplayMode) OVERRIDE;
 
     OwnPtr<HTMLImageLoader> m_imageLoader;
 
     AtomicString m_defaultPosterURL;
 };
 
 } //namespace
 
 #endif