Ensure acks are sent for all blocking events.

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 d06c0133182b4db742190df9ea87ddc116a80bc5..1935a2e04a363ca6e74861e14cce1d0ec193532b 100644
--- a/content/renderer/input/input_handler_manager.h
+++ b/content/renderer/input/input_handler_manager.h
@@ -67,7 +67,8 @@ class CONTENT_EXPORT InputHandlerManager {
       const cc::InputHandlerScrollResult& scroll_result);
 
   void NotifyInputEventHandledOnMainThread(int routing_id,
-                                           blink::WebInputEvent::Type);
+                                           blink::WebInputEvent::Type,
+                                           InputEventAckState);
 
   // Callback only from the compositor's thread.
   void RemoveInputHandler(int routing_id);
@@ -111,7 +112,8 @@ class CONTENT_EXPORT InputHandlerManager {
       const cc::InputHandlerScrollResult& scroll_result);
 
   void NotifyInputEventHandledOnCompositorThread(int routing_id,
-                                                 blink::WebInputEvent::Type);
+                                                 blink::WebInputEvent::Type,
+                                                 InputEventAckState);
 
   typedef base::ScopedPtrHashMap<int,  // routing_id
                                  std::unique_ptr<InputHandlerWrapper>>