Merge 75007 - Merge 73927

WebCore/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 47 matching lines @@
     virtual void canvasResized(HTMLCanvasElement*) = 0;
     virtual void canvasDestroyed(HTMLCanvasElement*) = 0;
 };
 
 class HTMLCanvasElement : public HTMLElement {
 public:
     static PassRefPtr<HTMLCanvasElement> create(Document*);
     static PassRefPtr<HTMLCanvasElement> create(const QualifiedName&, Document*);
     virtual ~HTMLCanvasElement();
 
-    void setObserver(CanvasObserver* observer) { m_observer = observer; }
+    void addObserver(CanvasObserver* observer);
+    void removeObserver(CanvasObserver* observer);
 
     // Attributes and functions exposed to script
     int width() const { return size().width(); }
     int height() const { return size().height(); }
 
     const IntSize& size() const { return m_size; }
 
     void setWidth(int);
     void setHeight(int);
 
@@ skipping 52 matching lines @@
 
     virtual void recalcStyle(StyleChange);
 
     void reset();
 
     void createImageBuffer() const;
 
     void setSurfaceSize(const IntSize&);
     bool hasCreatedImageBuffer() const { return m_hasCreatedImageBuffer; }
 
-    CanvasObserver* m_observer;
+    HashSet<CanvasObserver*> m_observers;
 
     IntSize m_size;
 
     OwnPtr<CanvasRenderingContext> m_context;
 
     bool m_rendererIsCanvas;
 
     bool m_ignoreReset;
     FloatRect m_dirtyRect;
 
     float m_pageScaleFactor;
     bool m_originClean;
 
     // m_createdImageBuffer means we tried to malloc the buffer.  We didn't necessarily get it.
     mutable bool m_hasCreatedImageBuffer;
     mutable OwnPtr<ImageBuffer> m_imageBuffer;
     
     mutable RefPtr<Image> m_copiedImage; // FIXME: This is temporary for platforms that have to copy the image buffer to render (and for CSSCanvasValue).
 };
 
 } //namespace
 
 #endif