Fixes drag and drop crash. The problem was when I made

ui/views/controls/menu/menu_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 UI_VIEWS_CONTROLS_MENU_MENU_CONTROLLER_H_
 #define UI_VIEWS_CONTROLS_MENU_MENU_CONTROLLER_H_
 #pragma once
 
 #include "build/build_config.h"
 
 #include <list>
 #include <set>
 #include <vector>
 
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop.h"
 #include "base/timer.h"
 #include "ui/base/events.h"
 #include "ui/views/controls/menu/menu_delegate.h"
 #include "ui/views/controls/menu/menu_item_view.h"
 
+#if defined(USE_AURA)
+namespace aura {
+class RootWindow;
+}
+#endif
+
 namespace ui {
 class OSExchangeData;
 }
-using ui::OSExchangeData;
-
 namespace views {
 
 class DropTargetEvent;
 class MenuButton;
 class MenuHostRootView;
 class MouseEvent;
 class SubmenuView;
 class View;
 
 namespace internal {
@@ skipping 65 matching lines @@
   void OnMouseEntered(SubmenuView* source, const MouseEvent& event);
 #if defined(OS_LINUX)
   bool OnMouseWheel(SubmenuView* source, const MouseWheelEvent& event);
 #endif
   ui::GestureStatus OnGestureEvent(SubmenuView* source,
                                    const GestureEvent& event);
 
   bool GetDropFormats(
       SubmenuView* source,
       int* formats,
-      std::set<OSExchangeData::CustomFormat>* custom_formats);
+      std::set<ui::OSExchangeData::CustomFormat>* custom_formats);
   bool AreDropTypesRequired(SubmenuView* source);
-  bool CanDrop(SubmenuView* source, const OSExchangeData& data);
+  bool CanDrop(SubmenuView* source, const ui::OSExchangeData& data);
   void OnDragEntered(SubmenuView* source, const DropTargetEvent& event);
   int OnDragUpdated(SubmenuView* source, const DropTargetEvent& event);
   void OnDragExited(SubmenuView* source);
   int OnPerformDrop(SubmenuView* source, const DropTargetEvent& event);
 
   // Invoked from the scroll buttons of the MenuScrollViewContainer.
   void OnDragEnteredScrollButton(SubmenuView* source, bool is_up);
   void OnDragExitedScrollButton(SubmenuView* source);
 
   // Invoked once for any Widget activation change.  This allows the menu
@@ skipping 362 matching lines @@
   // side.
   base::OneShotTimer<MenuController> cancel_all_timer_;
 
   // Drop target.
   MenuItemView* drop_target_;
   MenuDelegate::DropPosition drop_position_;
 
   // Owner of child windows.
   Widget* owner_;
 
+#if defined(USE_AURA)
+  // |owner_|s RootWindow. Cached as at the time we need it |owner_| may have
+  // been deleted.
+  aura::RootWindow* root_window_;
+#endif
+
   // Indicates a possible drag operation.
   bool possible_drag_;
 
   // True when drag operation is in progress.
   bool drag_in_progress_;
 
   // Location the mouse was pressed at. Used to detect d&d.
   gfx::Point press_pt_;
 
   // We get a slew of drag updated messages as the mouse is over us. To avoid
@@ skipping 20 matching lines @@
   // How deep we are in nested message loops. This should be at most 2 (when
   // showing a context menu from a menu).
   int message_loop_depth_;
 
   DISALLOW_COPY_AND_ASSIGN(MenuController);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_CONTROLS_MENU_MENU_CONTROLLER_H_