Use a union typdef for the return type of canvas.getContext

third_party/WebKit/Source/modules/webgl/WebGLRenderingContext.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 35 matching lines @@
         CanvasRenderingContext::ContextType getContextType() const override { return CanvasRenderingContext::ContextWebgl; }
         void onError(HTMLCanvasElement*, const String& error) override;
     };
 
     ~WebGLRenderingContext() override;
 
     CanvasRenderingContext::ContextType getContextType() const override { return CanvasRenderingContext::ContextWebgl; }
     unsigned version() const override { return 1; }
     String contextName() const override { return "WebGLRenderingContext"; }
     void registerContextExtensions() override;
+    void setCanvasGetContextResult(RenderingContext&) final;
 
     EAGERLY_FINALIZE();
     DECLARE_VIRTUAL_TRACE();
 
 private:
     WebGLRenderingContext(HTMLCanvasElement*, PassOwnPtr<WebGraphicsContext3D>, const WebGLContextAttributes&);
 
     // Enabled extension objects.
     PersistentWillBeMember<ANGLEInstancedArrays> m_angleInstancedArrays;
     PersistentWillBeMember<CHROMIUMSubscribeUniform> m_chromiumSubscribeUniform;
@@ skipping 22 matching lines @@
     PersistentWillBeMember<WebGLDepthTexture> m_webglDepthTexture;
 };
 
 DEFINE_TYPE_CASTS(WebGLRenderingContext, CanvasRenderingContext, context,
     context->is3d() && WebGLRenderingContextBase::getWebGLVersion(context) == 1,
     context.is3d() && WebGLRenderingContextBase::getWebGLVersion(&context) == 1);
 
 } // namespace blink
 
 #endif // WebGLRenderingContext_h