[VSync Queue] Plug touch ack to gesture events and flush vsync queue if necessary

ui/events/event_constants.h

 // Copyright (c) 2012 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.
 
 #ifndef UI_EVENTS_EVENT_CONSTANTS_H_
 #define UI_EVENTS_EVENT_CONSTANTS_H_
 
 namespace ui {
 
 // Event types. (prefixed because of a conflict with windows headers)
@@ skipping 135 matching lines @@
                          // propagated to other handlers.
   ER_HANDLED = 1 << 0,   // The event has already been handled, but it can
                          // still be propagated to other handlers.
   ER_CONSUMED = 1 << 1,  // The event has been handled, and it should not be
                          // propagated to other handlers.
   ER_DISABLE_SYNC_HANDLING =
       1 << 2,  // The event shouldn't be handled synchronously. This
                // happens if the event is being handled
                // asynchronously, or if the event is invalid and
                // shouldn't be handled at all.
+  ER_IGNORED_NON_BLOCKING =

[dtapuska, 2017/05/25 15:40:12]

The name is slightly confusing because this is a bit set.

sadrul@ might have a comment here.

+      1 << 3,  // The event was dispatched non-blocking, a synthetic ack has
+               // been received.
 };
 
 // Phase of the event dispatch.
 enum EventPhase {
   EP_PREDISPATCH,
   EP_PRETARGET,
   EP_TARGET,
   EP_POSTTARGET,
   EP_POSTDISPATCH
 };
@@ skipping 34 matching lines @@
 // Device type for gesture events.
 enum class GestureDeviceType : int {
   DEVICE_UNKNOWN = 0,
   DEVICE_TOUCHPAD,
   DEVICE_TOUCHSCREEN,
 };
 
 }  // namespace ui
 
 #endif  // UI_EVENTS_EVENT_CONSTANTS_H_