Exposes more mutation functions to MotionEventGeneric

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"
 
 namespace ui {
 
@@ skipping 179 matching lines @@
 // static
 scoped_ptr<MotionEventGeneric> MotionEventGeneric::CancelEvent(
     const MotionEvent& event) {
   bool with_history = false;
   scoped_ptr<MotionEventGeneric> cancel_event(
       new MotionEventGeneric(event, with_history));
   cancel_event->set_action(ACTION_CANCEL);
   return cancel_event.Pass();
 }
 
-void MotionEventGeneric::PushPointer(const PointerProperties& pointer) {
+size_t MotionEventGeneric::PushPointer(const PointerProperties& pointer) {
   DCHECK_EQ(0U, GetHistorySize());
   pointers_->push_back(pointer);
+  return pointers_->size() - 1;
+}
+
+void MotionEventGeneric::RemovePointerAt(size_t index) {
+  DCHECK_LT(index, pointers_->size());
+  pointers_->erase(pointers_->begin() + index);
 }
 
 void MotionEventGeneric::PushHistoricalEvent(scoped_ptr<MotionEvent> event) {
   DCHECK(event);
   DCHECK_EQ(event->GetAction(), ACTION_MOVE);
   DCHECK_EQ(event->GetPointerCount(), GetPointerCount());
   DCHECK_EQ(event->GetAction(), GetAction());
   DCHECK_LE(event->GetEventTime().ToInternalValue(),
             GetEventTime().ToInternalValue());
   historical_events_.push_back(event.release());
@@ skipping 50 matching lines @@
     PushHistoricalEvent(other.historical_events_[h]->Clone());
   return *this;
 }
 
 void MotionEventGeneric::PopPointer() {
   DCHECK_GT(pointers_->size(), 0U);
   pointers_->pop_back();
 }
 
 }  // namespace ui