Make sure send one WebTouchEvent ack per ui::TouchEvent

ui/events/gesture_detection/motion_event_generic.cc

 // Copyright 2014 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 "ui/events/gesture_detection/motion_event_generic.h"
 
 #include "base/logging.h"
 #include "ui/events/base_event_utils.h"
 
 namespace ui {
@@ skipping 61 matching lines @@
 
 uint32 MotionEventGeneric::GetUniqueEventId() const {
   return unique_event_id_;
 }
 
 MotionEvent::Action MotionEventGeneric::GetAction() const {
   return action_;
 }
 
 int MotionEventGeneric::GetActionIndex() const {
-  DCHECK(action_ == ACTION_POINTER_DOWN || action_ == ACTION_POINTER_UP);
+  DCHECK(action_ != ACTION_DOWN && action_ != ACTION_UP);
   DCHECK_GE(action_index_, 0);
   DCHECK_LT(action_index_, static_cast<int>(pointers_->size()));
   return action_index_;
 }
 
 size_t MotionEventGeneric::GetPointerCount() const {
   return pointers_->size();
 }
 
 int MotionEventGeneric::GetPointerId(size_t pointer_index) const {
@@ skipping 181 matching lines @@
     PushHistoricalEvent(other.historical_events_[h]->Clone());
   return *this;
 }
 
 void MotionEventGeneric::PopPointer() {
   DCHECK_GT(pointers_->size(), 0U);
   pointers_->pop_back();
 }
 
 }  // namespace ui