Desktop Aura: Allow tab drags out of window.

ui/views/widget/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_NATIVE_WIDGET_HELPER_AURA_H_
 #define UI_VIEWS_WIDGET_NATIVE_WIDGET_HELPER_AURA_H_
 
 #include "ui/views/views_export.h"
 #include "ui/views/widget/widget.h"
 
 namespace views {
 
 // A special delegate that encapsulates all logic for use of NativeWidgetAura
 // on the desktop.
 class VIEWS_EXPORT NativeWidgetHelperAura {
  public:
   virtual ~NativeWidgetHelperAura() {}
 
   // Called at the start of InitNativeWidget; determines whether we should
   // set up a root_window_ for this widget/window pair.
   virtual void PreInitialize(aura::Window* window,
                              const Widget::InitParams& params) = 0;
 
   // Called at the end of InitNativeWidget; i.e. after the NativeWidgetAura's
   // aura::Window has been initialized.
   virtual void PostInitialize() = 0;
 
-  // Passes through a message to show the RootWindow, if it exists.
-  virtual void ShowRootWindow() = 0;
-
   // If we own a RootWindow, return it. Otherwise NULL.
   virtual aura::RootWindow* GetRootWindow() = 0;
 
   // If this NativeWidgetAura has its own RootWindow, sets the position at the
   // |root_window_|, and returns modified bounds to set the origin to
   // zero. Otherwise, pass through in_bounds.
   virtual gfx::Rect ModifyAndSetBounds(const gfx::Rect& bounds) = 0;
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_WIDGET_NATIVE_WIDGET_HELPER_AURA_H_