Set the unique_event_id when converting from TouchEvent to WebTouchEvent

content/common/input/synthetic_web_input_event_builders.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/synthetic_web_input_event_builders.h"
 
 #include "base/logging.h"
 #include "content/common/input/web_touch_event_traits.h"
 #include "ui/events/keycodes/keyboard_codes.h"
 
 namespace content {
 
+namespace {
+
+uint64 get_next_event_id() {

[tdresser, 2015/04/08 12:24:26]

Can we factor this method out into a helper somewhere? Perhaps something in the
events_base target would work?

[lanwei, 2015/04/09 04:14:28]

Done.

+  // Set the first unique_id_ to 1 because we set id to 0 for other types
+  // of events.
+  static uint64 id = 1;
+  if (id==0)
+    id++;
+  DCHECK_NE(id, 0UL);
+  return id++;
+}
+
+} // namespace
+
 using blink::WebInputEvent;
 using blink::WebKeyboardEvent;
 using blink::WebGestureEvent;
 using blink::WebMouseEvent;
 using blink::WebMouseWheelEvent;
 using blink::WebTouchEvent;
 using blink::WebTouchPoint;
 
 WebMouseEvent SyntheticWebMouseEventBuilder::Build(
     blink::WebInputEvent::Type type) {
@@ skipping 120 matching lines @@
     float velocity_y,
     blink::WebGestureDevice source_device) {
   WebGestureEvent result = Build(WebInputEvent::GestureFlingStart,
                                  source_device);
   result.data.flingStart.velocityX = velocity_x;
   result.data.flingStart.velocityY = velocity_y;
   return result;
 }
 
 SyntheticWebTouchEvent::SyntheticWebTouchEvent() : WebTouchEvent() {
+  uniqueTouchEventId = get_next_event_id();
   SetTimestamp(base::TimeTicks::Now() - base::TimeTicks());
 }
 
 void SyntheticWebTouchEvent::ResetPoints() {
   int point = 0;
   for (unsigned int i = 0; i < touchesLength; ++i) {
     if (touches[i].state == WebTouchPoint::StateReleased)
       continue;
 
     touches[point] = touches[i];
@@ skipping 50 matching lines @@
   touches[index].state = WebTouchPoint::StateCancelled;
   WebTouchEventTraits::ResetType(
       WebInputEvent::TouchCancel, timeStampSeconds, this);
 }
 
 void SyntheticWebTouchEvent::SetTimestamp(base::TimeDelta timestamp) {
   timeStampSeconds = timestamp.InSecondsF();
 }
 
 }  // namespace content