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

content/browser/renderer_host/input/passthrough_touch_event_queue.cc

 // Copyright 2017 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/browser/renderer_host/input/passthrough_touch_event_queue.h"
 
 #include <utility>
 
 #include "base/auto_reset.h"
 #include "base/macros.h"
@@ skipping 235 matching lines @@
 }
 
 bool PassthroughTouchEventQueue::IsAckTimeoutEnabled() const {
   return timeout_handler_ && timeout_handler_->IsEnabled();
 }
 
 bool PassthroughTouchEventQueue::Empty() const {
   return outstanding_touches_.empty();
 }
 
+bool PassthroughTouchEventQueue::SendTouchEventsAsync() const {
+  return send_touch_events_async_;
+}
+
 void PassthroughTouchEventQueue::FlushQueue() {
   drop_remaining_touches_in_sequence_ = true;
   while (!outstanding_touches_.empty()) {
     auto iter = outstanding_touches_.begin();
     TouchEventWithLatencyInfoAndAckState event = *iter;
     outstanding_touches_.erase(iter);
     if (event.ack_state() == INPUT_EVENT_ACK_STATE_UNKNOWN)
       event.set_ack_state(INPUT_EVENT_ACK_STATE_NO_CONSUMER_EXISTS);
     AckTouchEventToClient(event, event.ack_state());
   }
@@ skipping 177 matching lines @@
 bool PassthroughTouchEventQueue::IsTimeoutRunningForTesting() const {
   return timeout_handler_ && timeout_handler_->IsTimeoutTimerRunning();
 }
 
 const TouchEventWithLatencyInfo&
 PassthroughTouchEventQueue::GetLatestEventForTesting() const {
   return *outstanding_touches_.rbegin();
 }
 
 }  // namespace content