Fix a crash in DesktopNativeWidgetHelperAura when closing tabs because it was dereferncing a delete…

ui/views/widget/desktop_native_widget_helper_aura.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_WIDGET_DESKTOP_NATIVE_WIDGET_HELPER_AURA_H_
 #define UI_VIEWS_WIDGET_DESKTOP_NATIVE_WIDGET_HELPER_AURA_H_
 
 #include "ui/aura/root_window_observer.h"
 #include "ui/aura/window_observer.h"
 #include "ui/gfx/rect.h"
@@ skipping 45 matching lines @@
   static aura::Window* GetViewsWindowForRootWindow(aura::RootWindow* root);
 
   // Overridden from aura::NativeWidgetHelperAura:
   virtual void PreInitialize(aura::Window* window,
                              const Widget::InitParams& params) OVERRIDE;
   virtual void PostInitialize() OVERRIDE;
   virtual aura::RootWindow* GetRootWindow() OVERRIDE;
   virtual gfx::Rect ModifyAndSetBounds(const gfx::Rect& bounds) OVERRIDE;
 
   // Overridden from aura::RootWindowObserver:
+  virtual void OnWindowDestroying(aura::Window* window) OVERRIDE;
+
+  // Overridden from aura::RootWindowObserver:
   virtual void OnRootWindowResized(const aura::RootWindow* root,
                                    const gfx::Size& old_size) OVERRIDE;
   virtual void OnRootWindowMoved(const aura::RootWindow* root,
                                  const gfx::Point& new_origin) OVERRIDE;
   virtual void OnWindowVisibilityChanged(aura::Window* window,
                                          bool visible) OVERRIDE;
   virtual void OnRootWindowHostCloseRequested(
                                    const aura::RootWindow* root) OVERRIDE;
 
  private:
@@ skipping 37 matching lines @@
   scoped_ptr<X11WindowEventFilter> x11_window_event_filter_;
   scoped_ptr<X11DesktopWindowMoveClient> x11_window_move_client_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(DesktopNativeWidgetHelperAura);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_WIDGET_DESKTOP_NATIVE_WIDGET_HELPER_AURA_H_