Make tap gesture ignore its ack disposition.

content/common/input/web_input_event_traits.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/common/input/web_input_event_traits.h"
 
 #include "base/logging.h"
 
 using blink::WebGestureEvent;
 using blink::WebInputEvent;
@@ skipping 271 matching lines @@
   DCHECK(event);
   Apply(WebInputEventCoalesce(), event->type, event_to_coalesce, event);
 }
 
 bool WebInputEventTraits::IgnoresAckDisposition(
     blink::WebInputEvent::Type type) {
   switch (type) {
     case WebInputEvent::GestureTapDown:
     case WebInputEvent::GestureShowPress:
     case WebInputEvent::GestureTapCancel:
+    case WebInputEvent::GestureTap:
     case WebInputEvent::GesturePinchBegin:
     case WebInputEvent::GesturePinchEnd:
     case WebInputEvent::GestureScrollBegin:
     case WebInputEvent::GestureScrollEnd:
     case WebInputEvent::TouchCancel:
     case WebInputEvent::MouseDown:
     case WebInputEvent::MouseUp:
     case WebInputEvent::MouseEnter:
     case WebInputEvent::MouseLeave:
     case WebInputEvent::ContextMenu:
       return true;
     default:
       break;
   }
   return false;
 }
 
 }  // namespace content