Update WindowTree::OnWindowInputEventAck to include handled

components/mus/public/interfaces/window_tree.mojom

Index: components/mus/public/interfaces/window_tree.mojom
diff --git a/components/mus/public/interfaces/window_tree.mojom b/components/mus/public/interfaces/window_tree.mojom
index 5114297483828adedb1588f28466c90ea90faf2e..09d297281f811069e28ea36ad8ab64592c79a9bc 100644
--- a/components/mus/public/interfaces/window_tree.mojom
+++ b/components/mus/public/interfaces/window_tree.mojom
@@ -246,7 +246,7 @@ interface WindowTree {
   SetImeVisibility(uint32 window_id, bool visible, mojo.TextInputState? state);
 
   // See documentation for WindowTreeClient::OnWindowInputEvent().
-  OnWindowInputEventAck(uint32 event_id);
+  OnWindowInputEventAck(uint32 event_id, bool handled);
 
   // See description of WindowManager for details.
   GetWindowManagerClient(associated WindowManagerClient& internal);
@@ -350,8 +350,9 @@ interface WindowTreeClient {
 
   // Invoked when an event is targeted at the specified window. The client must
   // call WindowTree::OnWindowInputEventAck() with the same |event_id| to notify
-  // that the event has been processed. The client will not receive farther
-  // events until the event is ack'ed.
+  // that the event has been processed, and with a boolean |handled| to notify
+  // if the event was consumed. The client will not receive farther events until
+  // the event is ack'ed.
   OnWindowInputEvent(uint32 event_id, uint32 window, Event event);
 
   OnWindowFocused(uint32 focused_window_id);