Adding cache for security origin validations in 2D/WebGL canvases

Source/core/html/canvas/CanvasRenderingContext.h

 /*
  * Copyright (C) 2009 Apple Inc. 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.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 18 matching lines @@
 #include "core/html/HTMLCanvasElement.h"
 #include "platform/heap/Handle.h"
 #include "wtf/HashSet.h"
 #include "wtf/Noncopyable.h"
 #include "wtf/text/StringHash.h"
 
 namespace blink { class WebLayer; }
 
 namespace WebCore {
 
+class CanvasImageSource;
 class HTMLCanvasElement;
 class KURL;
 class WebGLObject;
 
 class CanvasRenderingContext : public NoBaseWillBeGarbageCollectedFinalized<CanvasRenderingContext> {
     WTF_MAKE_NONCOPYABLE(CanvasRenderingContext);
     WTF_MAKE_FAST_ALLOCATED_WILL_BE_REMOVED;
 public:
     virtual ~CanvasRenderingContext() { }
 
 #if !ENABLE(OILPAN)
     void ref() { m_canvas->ref(); }
     void deref() { m_canvas->deref(); }
 #endif
 
     HTMLCanvasElement* canvas() const { return m_canvas; }
 
     virtual bool is2d() const { return false; }
     virtual bool is3d() const { return false; }
     virtual bool isAccelerated() const { return false; }
     virtual bool hasAlpha() const { return true; }
 
     virtual void paintRenderingResultsToCanvas() {}
 
     virtual blink::WebLayer* platformLayer() const { return 0; }
 
     virtual void trace(Visitor* visitor) { visitor->trace(m_canvas); }
 
+    bool wouldTaintOrigin(CanvasImageSource*);
+
 protected:
     CanvasRenderingContext(HTMLCanvasElement*);
 
 private:
     RawPtrWillBeMember<HTMLCanvasElement> m_canvas;
+    HashSet<String> m_cleanURLs;
+    HashSet<String> m_dirtyURLs;
 };
 
 } // namespace WebCore
 
 #endif