Implement OffscreenCanvas.getContext('webgl')

third_party/WebKit/Source/core/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"
 #include "core/html/HTMLCanvasElement.h"
 #include "platform/geometry/IntSize.h"
 #include "platform/heap/Handle.h"
 
 namespace blink {
 
 class CanvasContextCreationAttributes;
 class ImageBitmap;
+class OffscreenCanvasRenderingContext2DOrWebGLRenderingContextOrWebGL2RenderingContext;
+typedef OffscreenCanvasRenderingContext2DOrWebGLRenderingContextOrWebGL2RenderingContext OffscreenRenderingContext;
 
 class CORE_EXPORT OffscreenCanvas final : public GarbageCollected<OffscreenCanvas>, public ScriptWrappable {
     DEFINE_WRAPPERTYPEINFO();
 public:
     static OffscreenCanvas* create(unsigned width, unsigned height);
 
     // IDL attributes
     unsigned width() const { return m_size.width(); }
     unsigned height() const { return m_size.height(); }
     void setWidth(unsigned);
     void setHeight(unsigned);
 
     // API Methods
     ImageBitmap* transferToImageBitmap(ExceptionState&);
 
     IntSize size() const { return m_size; }
     void setAssociatedCanvas(HTMLCanvasElement* canvas) { m_canvas = canvas; }
     HTMLCanvasElement* getAssociatedCanvas() const { return m_canvas; }
-    CanvasRenderingContext* getCanvasRenderingContext(const String&, const CanvasContextCreationAttributes&);
+    CanvasRenderingContext* getCanvasRenderingContext(ScriptState*, const String&, const CanvasContextCreationAttributes&);
 
     static void registerRenderingContextFactory(PassOwnPtr<CanvasRenderingContextFactory>);
 
     DECLARE_VIRTUAL_TRACE();
 
 private:
     explicit OffscreenCanvas(const IntSize&);
 
     using ContextFactoryVector = Vector<OwnPtr<CanvasRenderingContextFactory>>;
     static ContextFactoryVector& renderingContextFactories();
     static CanvasRenderingContextFactory* getRenderingContextFactory(int);
 
     Member<CanvasRenderingContext> m_context;
     WeakMember<HTMLCanvasElement> m_canvas;
     IntSize m_size;
 };
 
 } // namespace blink
 
 #endif // OffscreenCanvas_h