Re-land "WebGL: Transfer ownership of WebGraphicsContext3D to DrawingBuffer"

Source/core/html/canvas/WebGLRenderingContext.cpp

 /*
  * 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 78 matching lines @@
     }
 
     Extensions3DUtil extensionsUtil(context.get());
     if (extensionsUtil.supportsExtension("GL_EXT_debug_marker"))
         context->pushGroupMarkerEXT("WebGLRenderingContext");
 
     OwnPtr<WebGLRenderingContext> renderingContext = adoptPtr(new WebGLRenderingContext(canvas, context.release(), attrs));
     renderingContext->registerContextExtensions();
     renderingContext->suspendIfNeeded();
 
-    if (renderingContext->m_drawingBuffer->isZeroSized()) {
+    if (!renderingContext->m_drawingBuffer) {
         canvas->dispatchEvent(WebGLContextEvent::create(EventTypeNames::webglcontextcreationerror, false, true, "Could not create a WebGL context."));
         return nullptr;
     }
 
     return renderingContext.release();
 }
 
 WebGLRenderingContext::WebGLRenderingContext(HTMLCanvasElement* passedCanvas, PassOwnPtr<blink::WebGraphicsContext3D> context, WebGLContextAttributes* requestedAttributes)
     : WebGLRenderingContextBase(passedCanvas, context, requestedAttributes)
 {
@@ skipping 29 matching lines @@
 
     // Register draft extensions.
     registerExtension<EXTFragDepth>(m_extFragDepth, DraftExtension);
 
     // Register privileged extensions.
     registerExtension<WebGLDebugRendererInfo>(m_webglDebugRendererInfo, WebGLDebugRendererInfoExtension);
     registerExtension<WebGLDebugShaders>(m_webglDebugShaders, PrivilegedExtension);
 }
 
 } // namespace WebCore