Implement OffscreenCanvas.getContext('webgl')

third_party/WebKit/Source/modules/webgl/WebGLRenderingContext.h

Index: third_party/WebKit/Source/modules/webgl/WebGLRenderingContext.h
diff --git a/third_party/WebKit/Source/modules/webgl/WebGLRenderingContext.h b/third_party/WebKit/Source/modules/webgl/WebGLRenderingContext.h
index e0f6a0b313dd55d7da2c93bb836e9a8d43533c44..b2f654879e08af288b634b3b86365866e8e1de00 100644
--- a/third_party/WebKit/Source/modules/webgl/WebGLRenderingContext.h
+++ b/third_party/WebKit/Source/modules/webgl/WebGLRenderingContext.h
@@ -43,6 +43,7 @@ public:
         ~Factory() override {}
 
         CanvasRenderingContext* create(HTMLCanvasElement*, const CanvasContextCreationAttributes&, Document&) override;
+        CanvasRenderingContext* create(ScriptState*, OffscreenCanvas*, const CanvasContextCreationAttributes&) override;
         CanvasRenderingContext::ContextType getContextType() const override { return CanvasRenderingContext::ContextWebgl; }
         void onError(HTMLCanvasElement*, const String& error) override;
     };
@@ -50,16 +51,19 @@ public:
     ~WebGLRenderingContext() override;
 
     CanvasRenderingContext::ContextType getContextType() const override { return CanvasRenderingContext::ContextWebgl; }
+    ImageBitmap* transferToImageBitmap(ExceptionState&) final;
     unsigned version() const override { return 1; }
     String contextName() const override { return "WebGLRenderingContext"; }
     void registerContextExtensions() override;
     void setCanvasGetContextResult(RenderingContext&) final;
+    void setOffscreenCanvasGetContextResult(OffscreenRenderingContext&) final;
 
     EAGERLY_FINALIZE();
     DECLARE_VIRTUAL_TRACE();
 
 private:
     WebGLRenderingContext(HTMLCanvasElement*, PassOwnPtr<WebGraphicsContext3DProvider>, const WebGLContextAttributes&);
+    WebGLRenderingContext(OffscreenCanvas*, PassOwnPtr<WebGraphicsContext3DProvider>, const WebGLContextAttributes&);
 
     // Enabled extension objects.
     Member<ANGLEInstancedArrays> m_angleInstancedArrays;