Eliminates all ash dependencies from WindowModalityController.

ui/aura/client/activation_client.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_AURA_CLIENT_ACTIVATION_CLIENT_H_
 #define UI_AURA_CLIENT_ACTIVATION_CLIENT_H_
 
 #include "ui/aura/aura_export.h"
 #include "ui/aura/window.h"
 
@@ skipping 17 matching lines @@
   // Activates |window|. If |window| is NULL, nothing happens.
   virtual void ActivateWindow(Window* window) = 0;
 
   // Deactivates |window|. What (if anything) is activated next is up to the
   // client. If |window| is NULL, nothing happens.
   virtual void DeactivateWindow(Window* window) = 0;
 
   // Retrieves the active window, or NULL if there is none.
   virtual Window* GetActiveWindow() = 0;
 
+  // Retrieves the activatable window for |window|, or NULL if there is none.
+  virtual Window* GetActivatableWindow(Window* window) = 0;
+
   // Invoked prior to |window| getting focus as a result of the |event|. |event|
   // may be NULL. Returning false blocks |window| from getting focus.
   virtual bool OnWillFocusWindow(Window* window, const ui::Event* event) = 0;
 
   // Returns true if |window| can be activated, false otherwise. If |window| has
   // a modal child it can not be activated.
   virtual bool CanActivateWindow(Window* window) const = 0;
 
  protected:
   virtual ~ActivationClient() {}
@@ skipping 11 matching lines @@
 // TODO(beng): currently the UI framework (views) implements the actual
 //             close-on-deactivate component of this feature but it should be
 //             possible to implement in the aura client.
 AURA_EXPORT void SetHideOnDeactivate(Window* window, bool hide_on_deactivate);
 AURA_EXPORT bool GetHideOnDeactivate(Window* window);
 
 }  // namespace clients
 }  // namespace aura
 
 #endif  // UI_AURA_CLIENT_ACTIVATION_CLIENT_H_