Revert 258077 "Remove PrepareForShutdown"

trunk/src/ui/aura/window_event_dispatcher.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/aura/window_event_dispatcher.h"
 
 #include "base/bind.h"
 #include "base/debug/trace_event.h"
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
@@ skipping 74 matching lines @@
       repost_event_factory_(this),
       held_event_factory_(this) {
   ui::GestureRecognizer::Get()->AddGestureEventHelper(this);
 }
 
 WindowEventDispatcher::~WindowEventDispatcher() {
   TRACE_EVENT0("shutdown", "WindowEventDispatcher::Destructor");
   ui::GestureRecognizer::Get()->RemoveGestureEventHelper(this);
 }
 
+void WindowEventDispatcher::PrepareForShutdown() {
+  host_->PrepareForShutdown();
+  // discard synthesize event request as well.
+  synthesize_mouse_move_ = false;
+}
+
 void WindowEventDispatcher::RepostEvent(const ui::LocatedEvent& event) {
   DCHECK(event.type() == ui::ET_MOUSE_PRESSED ||
          event.type() == ui::ET_GESTURE_TAP_DOWN);
   // We allow for only one outstanding repostable event. This is used
   // in exiting context menus.  A dropped repost request is allowed.
   if (event.type() == ui::ET_MOUSE_PRESSED) {
     held_repostable_event_.reset(
         new ui::MouseEvent(
             static_cast<const ui::MouseEvent&>(event),
             static_cast<aura::Window*>(event.target()),
@@ skipping 684 matching lines @@
       break;
 
     default:
       NOTREACHED();
       break;
   }
   PreDispatchLocatedEvent(target, event);
 }
 
 }  // namespace aura