Initialize and set compositor thread in WebKit initialization

content/renderer/render_thread.h

Index: content/renderer/render_thread.h
diff --git a/content/renderer/render_thread.h b/content/renderer/render_thread.h
index 3aacab51b88f5108651fbc3172fcd0be4ae73e69..95af0b0695906cbe690e1b845e127794c8eeda86 100644
--- a/content/renderer/render_thread.h
+++ b/content/renderer/render_thread.h
@@ -56,6 +56,7 @@ struct ChannelHandle;
 
 namespace WebKit {
 class WebStorageEventDispatcher;
+class WebThread;
 }
 
 namespace v8 {
@@ -276,6 +277,8 @@ class CONTENT_EXPORT RenderThread : public RenderThreadBase,
   // Map of registered v8 extensions. The key is the extension name.
   std::set<std::string> v8_extensions_;
 
+  scoped_ptr<WebKit::WebThread> compositor_thread_;
+
   ObserverList<RenderProcessObserver> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderThread);