Implement OffscreenCanvas.getContext('webgl')

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

Index: third_party/WebKit/Source/modules/offscreencanvas/OffscreenCanvas.cpp
diff --git a/third_party/WebKit/Source/modules/offscreencanvas/OffscreenCanvas.cpp b/third_party/WebKit/Source/modules/offscreencanvas/OffscreenCanvas.cpp
index 0aedca56e420feed6780983a749a355e6a8f3cd2..3ffe09ea9a7cde9acfce5fddc13d9aeb6afdb141 100644
--- a/third_party/WebKit/Source/modules/offscreencanvas/OffscreenCanvas.cpp
+++ b/third_party/WebKit/Source/modules/offscreencanvas/OffscreenCanvas.cpp
@@ -35,31 +35,31 @@ void OffscreenCanvas::setHeight(unsigned height)
     m_size.setHeight(clampTo<int>(height));
 }
 
-OffscreenCanvasRenderingContext2D* OffscreenCanvas::getContext(const String& id, const CanvasContextCreationAttributes& attributes)
+void OffscreenCanvas::getContext(ScriptState* scriptState, const String& id, const CanvasContextCreationAttributes& attributes, OffscreenRenderingContext& result)
 {
     OffscreenCanvasRenderingContext::ContextType contextType = OffscreenCanvasRenderingContext::contextTypeFromId(id);
 
     // Unknown type.
     if (contextType == OffscreenCanvasRenderingContext::ContextTypeCount)
-        return nullptr;
+        return;
 
     OffscreenCanvasRenderingContextFactory* factory = getRenderingContextFactory(contextType);
     if (!factory)
-        return nullptr;
+        return;
 
     if (m_context) {
-        if (m_context->getContextType() != contextType) {
+        if (m_context->getOffscreenCanvasRenderingContextType() != contextType) {
             factory->onError(this, "OffscreenCanvas has an existing context of a different type");
-            return nullptr;
+            return;
         }
     } else {
-        m_context = factory->create(this, attributes);
+        m_context = factory->create(scriptState, this, attributes);
     }
 
     // TODO: When there're more than one context type implemented in the future,
     // the return type here should be changed to base class of all Offscreen
     // context types.
-    return static_cast<OffscreenCanvasRenderingContext2D*>(m_context.get());
+    m_context->setOffscreenCanvasGetContextResult(result);
 }
 
 ImageBitmap* OffscreenCanvas::transferToImageBitmap(ExceptionState& exceptionState)
@@ -76,12 +76,12 @@ ImageBitmap* OffscreenCanvas::transferToImageBitmap(ExceptionState& exceptionSta
     return image;
 }
 
-OffscreenCanvasRenderingContext2D* OffscreenCanvas::renderingContext() const
+OffscreenCanvasRenderingContext* OffscreenCanvas::renderingContext() const
 {
     // TODO: When there're more than one context type implemented in the future,
     // the return type here should be changed to base class of all Offscreen
     // context types.
-    return static_cast<OffscreenCanvasRenderingContext2D*>(m_context.get());
+    return m_context.get();
 }
 
 OffscreenCanvas::ContextFactoryVector& OffscreenCanvas::renderingContextFactories()