Update WindowTree::OnWindowInputEventAck to include handled

components/mus/public/cpp/input_event_handler.h

Index: components/mus/public/cpp/input_event_handler.h
diff --git a/components/mus/public/cpp/input_event_handler.h b/components/mus/public/cpp/input_event_handler.h
index ebd159717f58f48c16b513f5cb33b3171a4b20c7..597653ba3d487163b8ad607b19d68ca8f898a6d5 100644
--- a/components/mus/public/cpp/input_event_handler.h
+++ b/components/mus/public/cpp/input_event_handler.h
@@ -16,11 +16,14 @@ class Window;
 class InputEventHandler {
  public:
   // The event handler can asynchronously ack the event by taking ownership of
-  // the |ack_callback|. If the handler does not take ownership of the callback,
-  // then WindowTreeClientImpl will ack the event.
-  virtual void OnWindowInputEvent(Window* target,
-                                  mojom::EventPtr event,
-                                  scoped_ptr<base::Closure>* ack_callback) = 0;
+  // the |ack_callback|. The callback takes a bool representing whether the
+  // handler has consumed the event. If the handler does not take ownership of
+  // the callback, then WindowTreeClientImpl will ack the event as not consumed.
+  virtual void OnWindowInputEvent(
+      Window* target,
+      mojom::EventPtr event,
+      scoped_ptr<base::Callback<void(bool)>>* ack_callback) = 0;
+
  protected:
   virtual ~InputEventHandler() {}
 };