cc: Implement shared worker contexts.

content/renderer/render_widget.cc

Index: content/renderer/render_widget.cc
diff --git a/content/renderer/render_widget.cc b/content/renderer/render_widget.cc
index fa599bea16ebc17127091e5d8295c039d03064c8..13c4984679392b71f520ca88a8c42f2108f801b7 100644
--- a/content/renderer/render_widget.cc
+++ b/content/renderer/render_widget.cc
@@ -1019,10 +1019,9 @@ scoped_ptr<cc::OutputSurface> RenderWidget::CreateOutputSurface(bool fallback) {
       // Cause the compositor to wait and try again.
       return scoped_ptr<cc::OutputSurface>();
     }
-
-    worker_context_provider = ContextProviderCommandBuffer::Create(
-        CreateGraphicsContext3D(false), RENDER_WORKER_CONTEXT);
-    if (!worker_context_provider.get()) {
+    worker_context_provider =
+        RenderThreadImpl::current()->SharedWorkerContextProvider();
+    if (!worker_context_provider) {
       // Cause the compositor to wait and try again.
       return scoped_ptr<cc::OutputSurface>();
     }