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

Source/core/html/canvas/WebGLRenderingContext.cpp

Index: Source/core/html/canvas/WebGLRenderingContext.cpp
diff --git a/Source/core/html/canvas/WebGLRenderingContext.cpp b/Source/core/html/canvas/WebGLRenderingContext.cpp
index b0f5542b7474a719a86b938f0546fda843465889..7d76e25a2198d2df17b1d797334dfcffa8039f66 100644
--- a/Source/core/html/canvas/WebGLRenderingContext.cpp
+++ b/Source/core/html/canvas/WebGLRenderingContext.cpp
@@ -96,7 +96,7 @@ PassOwnPtr<WebGLRenderingContext> WebGLRenderingContext::create(HTMLCanvasElemen
     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;
     }