Ensure acks are sent for all blocking events.

content/renderer/input/render_widget_input_handler_delegate.h

Index: content/renderer/input/render_widget_input_handler_delegate.h
diff --git a/content/renderer/input/render_widget_input_handler_delegate.h b/content/renderer/input/render_widget_input_handler_delegate.h
index 195c6716fbe10c69fd82a0634a2c414331272837..bbb58d006be80cfab129b22e88e6ce30b5a4a6c1 100644
--- a/content/renderer/input/render_widget_input_handler_delegate.h
+++ b/content/renderer/input/render_widget_input_handler_delegate.h
@@ -63,8 +63,8 @@ class CONTENT_EXPORT RenderWidgetInputHandlerDelegate {
   // Called when an event with a notify dispatch type
   // (DISPATCH_TYPE_*_NOTIFY_MAIN) of |handled_type| has been processed
   // by the main thread.
-  virtual void NotifyInputEventHandled(
-      blink::WebInputEvent::Type handled_type) = 0;
+  virtual void NotifyInputEventHandled(blink::WebInputEvent::Type handled_type,
+                                       InputEventAckState ack_result) = 0;
 
   // Notifies the delegate of the |input_handler| managing it.
   virtual void SetInputHandler(RenderWidgetInputHandler* input_handler) = 0;