Prevents reentrant CompleteDrag when changing display configuration

ash/wm/toplevel_window_event_handler.cc

 // Copyright (c) 2012 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 "ash/wm/toplevel_window_event_handler.h"
 
 #include "ash/shell.h"
 #include "ash/wm/resize_shadow_controller.h"
 #include "ash/wm/window_resizer.h"
 #include "ash/wm/window_state.h"
@@ skipping 358 matching lines @@
   in_gesture_drag_ = in_move_loop_ = false;
   return move_cancelled_ ? aura::client::MOVE_CANCELED :
       aura::client::MOVE_SUCCESSFUL;
 }
 
 void ToplevelWindowEventHandler::EndMoveLoop() {
   if (!in_move_loop_)
     return;
 
   in_move_loop_ = false;
-  if (window_resizer_) {
-    window_resizer_->resizer()->RevertDrag();
-    window_resizer_.reset();
-  }
+  CompleteDrag(DRAG_REVERT, 0);
   quit_closure_.Run();
 }
 
 void ToplevelWindowEventHandler::OnDisplayConfigurationChanging() {
   if (in_move_loop_) {
     move_cancelled_ = true;
     EndMoveLoop();
-  } else if (window_resizer_) {
-    window_resizer_->resizer()->RevertDrag();
-    window_resizer_.reset();
+  } else {
+    CompleteDrag(DRAG_REVERT, 0);
   }
 }
 
 void ToplevelWindowEventHandler::CreateScopedWindowResizer(
     aura::Window* window,
     const gfx::Point& point_in_parent,
     int window_component,
     aura::client::WindowMoveSource source) {
   window_resizer_.reset();
   WindowResizer* resizer =
@@ skipping 126 matching lines @@
 void ToplevelWindowEventHandler::ResizerWindowDestroyed() {
   // We explicitly don't invoke RevertDrag() since that may do things to window.
   // Instead we destroy the resizer.
   window_resizer_.reset();
 
   // End the move loop. This does nothing if we're not in a move loop.
   EndMoveLoop();
 }
 
 }  // namespace ash