Teach main thread event queue about closures.

content/renderer/input/input_handler_manager.h

Index: content/renderer/input/input_handler_manager.h
diff --git a/content/renderer/input/input_handler_manager.h b/content/renderer/input/input_handler_manager.h
index cd5be53cfe20c402f244f5d6ef63da7b7c2493ae..a66bf64ef46e7258ba7cb213b359a2425e2939b5 100644
--- a/content/renderer/input/input_handler_manager.h
+++ b/content/renderer/input/input_handler_manager.h
@@ -94,6 +94,9 @@ class CONTENT_EXPORT InputHandlerManager {
                                 const ui::LatencyInfo& latency_info,
                                 const InputEventAckStateCallback& callback);
 
+  virtual void QueueClosureForMainThreadEventQueue(
+      int routing_id,
+      const base::Closure& closure);
   // Called from the compositor's thread.
   void DidOverscroll(int routing_id, const ui::DidOverscrollParams& params);