Don't pass touches to gesture recognizer for async acks.

ui/events/gestures/gesture_recognizer_impl.cc

Index: ui/events/gestures/gesture_recognizer_impl.cc
diff --git a/ui/events/gestures/gesture_recognizer_impl.cc b/ui/events/gestures/gesture_recognizer_impl.cc
index 7250bf220580e260c7ed74d4cd89377f578d7028..774350353309cf1ddb1d63a94ce3c6dee94433f3 100644
--- a/ui/events/gestures/gesture_recognizer_impl.cc
+++ b/ui/events/gestures/gesture_recognizer_impl.cc
@@ -251,9 +251,11 @@ bool GestureRecognizerImpl::ProcessTouchEventPreDispatch(
   return gesture_provider->OnTouchEvent(event);
 }
 
+// TODO(tdresser): we should take a unique_event_id here, and validate
+// that the correct event is being acked. See crbug.com/457669 for
+// details.
 GestureRecognizer::Gestures*
 GestureRecognizerImpl::AckAsyncTouchEvent(
-    const TouchEvent& event,
     ui::EventResult result,
     GestureConsumer* consumer) {
   GestureProviderAura* gesture_provider =