Cancel drag if display configuration changes.

ash/root_window_controller.h

 // 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.
 
 #ifndef ASH_ROOT_WINDOW_CONTROLLER_H_
 #define ASH_ROOT_WINDOW_CONTROLLER_H_
 
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 
@@ skipping 41 matching lines @@
 
   internal::ScreenDimmer* screen_dimmer() {
     return screen_dimmer_.get();
   }
 
   aura::Window* GetContainer(int container_id);
 
   void CreateContainers();
   void InitLayoutManagers();
 
+  // Deletes associated objects and clears the state, but doesn't delete
+  // the root window yet. This is used to delete a secondary displays'
+  // root window safely when the display disconnect signal is received,
+  // which may come while we're in the nested message loop.
+  void Shutdown();
+
   // Deletes all child windows and performs necessary cleanup.
   void CloseChildWindows();
 
   // Returns true if the workspace has a maximized or fullscreen window.
   bool IsInMaximizedMode() const;
 
   // Moves child windows to |dest|.
   void MoveWindowsTo(aura::RootWindow* dest);
 
  private:
   scoped_ptr<aura::RootWindow> root_window_;
   internal::RootWindowLayoutManager* root_window_layout_;
 
   // An event filter that pre-handles all key events to send them to an IME.
   scoped_ptr<internal::EventClientImpl> event_client_;
   scoped_ptr<internal::ScreenDimmer> screen_dimmer_;
   scoped_ptr<internal::WorkspaceController> workspace_controller_;
 
   DISALLOW_COPY_AND_ASSIGN(RootWindowController);
 };
 
 }  // namespace internal
 }  // ash
 
 #endif  //  ASH_ROOT_WINDOW_CONTROLLER_H_