mustash: enable GPU Compositing in renderer

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 3f4c190c2c644a4e696b0d75070ebeee702ca03c..e0ed813360c09fbfd03afb3f82c651db847e273a 100644
--- a/content/renderer/render_widget.cc
+++ b/content/renderer/render_widget.cc
@@ -94,6 +94,11 @@
 #include "third_party/skia/include/core/SkPixelRef.h"
 #endif  // defined(OS_POSIX)
 
+#if defined(MOJO_SHELL_CLIENT)
+#include "content/public/common/mojo_shell_connection.h"
+#include "content/renderer/render_widget_mus_connection.h"
+#endif
+
 #include "third_party/WebKit/public/web/WebWidget.h"
 
 using blink::WebCompositionUnderline;
@@ -1013,6 +1018,14 @@ scoped_ptr<cc::OutputSurface> RenderWidget::CreateOutputSurface(bool fallback) {
   if (command_line.HasSwitch(switches::kDisableGpuCompositing))
     use_software = true;
 
+#if defined(MOJO_SHELL_CLIENT)
+  if (MojoShellConnection::Get() && !use_software) {
+    RenderWidgetMusConnection* connection =
+        RenderWidgetMusConnection::GetOrCreate(routing_id());
+    return connection->CreateOutputSurface();
+  }
+#endif
+
   scoped_refptr<ContextProviderCommandBuffer> context_provider;
   scoped_refptr<ContextProviderCommandBuffer> worker_context_provider;
   if (!use_software) {