Make OffscreenCanvas Transferable

third_party/WebKit/Source/modules/offscreencanvas/OffscreenCanvas.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef OffscreenCanvas_h
 #define OffscreenCanvas_h
 
 #include "bindings/core/v8/ScriptPromise.h"
 #include "bindings/core/v8/ScriptState.h"
 #include "bindings/core/v8/ScriptWrappable.h"
@@ skipping 16 matching lines @@
     static OffscreenCanvas* create(unsigned width, unsigned height);
     ~OffscreenCanvas();
 
     // IDL attributes
     unsigned width() const { return m_size.width(); }
     unsigned height() const { return m_size.height(); }
     void setWidth(unsigned);
     void setHeight(unsigned);
 
     // API Methods
-    OffscreenCanvasRenderingContext2D* getContext(const String&, const CanvasContextCreationAttributes&);
+    OffscreenCanvasRenderingContext2D* getContext(const String&, const CanvasContextCreationAttributes&, ExceptionState&);
     ImageBitmap* transferToImageBitmap(ExceptionState&);
 
     IntSize size() const { return m_size; }
     OffscreenCanvasRenderingContext2D* renderingContext() const;
-    void setAssociatedCanvas(HTMLCanvasElement* canvas) { m_canvas = canvas; }
-    HTMLCanvasElement* getAssociatedCanvas() const { return m_canvas; }
+    void setAssociatedCanvasId(int canvasId) { m_canvasId = canvasId; }
+    int getAssociatedCanvasId() const { return m_canvasId; }
+    bool isNeutered() const { return m_isNeutered; }
+    void setNeutered();
 
     static void registerRenderingContextFactory(PassOwnPtr<OffscreenCanvasRenderingContextFactory>);
 
     DECLARE_VIRTUAL_TRACE();
 
 private:
     OffscreenCanvas(const IntSize&);
 
     using ContextFactoryVector = Vector<OwnPtr<OffscreenCanvasRenderingContextFactory>>;
     static ContextFactoryVector& renderingContextFactories();
     static OffscreenCanvasRenderingContextFactory* getRenderingContextFactory(int);
 
     Member<OffscreenCanvasRenderingContext> m_context;
-    WeakMember<HTMLCanvasElement> m_canvas;
+    int m_canvasId = -1; // DOMNodeIds starts from 0, using -1 to indicate no associated canvas element.
     IntSize m_size;
+    bool m_isNeutered = false;
 };
 
 } // namespace blink
 
 #endif // OffscreenCanvas_h