Coalesce async touch move events until the ack back from render

content/browser/renderer_host/input/mock_input_ack_handler.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/browser/renderer_host/input/mock_input_ack_handler.h"
 
 #include "content/browser/renderer_host/input/input_router.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 using base::TimeDelta;
@@ skipping 29 matching lines @@
     InputEventAckState ack_result) {
   VLOG(1) << __FUNCTION__ << " called!";
   acked_wheel_event_ = event.event;
   RecordAckCalled(event.event.type, ack_result);
 }
 
 void MockInputAckHandler::OnTouchEventAck(
     const TouchEventWithLatencyInfo& event,
     InputEventAckState ack_result) {
   VLOG(1) << __FUNCTION__ << " called!";
+  LOG(ERROR) << "   MockInputAckHandler::OnTouchEventAck   ";
   acked_touch_event_ = event;
   RecordAckCalled(event.event.type, ack_result);
   if (touch_followup_event_)
     input_router_->SendTouchEvent(*touch_followup_event_);
   if (gesture_followup_event_)
     input_router_->SendGestureEvent(*gesture_followup_event_);
 }
 
 void MockInputAckHandler::OnGestureEventAck(
     const GestureEventWithLatencyInfo& event,
@@ skipping 15 matching lines @@
 }
 
 void MockInputAckHandler::RecordAckCalled(blink::WebInputEvent::Type type,
                                           InputEventAckState ack_result) {
   ack_event_type_ = type;
   ++ack_count_;
   ack_state_ = ack_result;
 }
 
 }  // namespace content