Add user action for changing the active window in Ash overview mode

ash/wm/overview/window_selector.h

 // Copyright 2013 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_WM_OVERVIEW_WINDOW_SELECTOR_H_
 #define ASH_WM_OVERVIEW_WINDOW_SELECTOR_H_
 
 #include <set>
 #include <vector>
 
@@ skipping 66 matching lines @@
 
   // Perform cleanup that cannot be done in the destructor.
   void Shutdown();
 
   // Cancels window selection.
   void CancelSelection();
 
   // Called when the last window selector item from a grid is deleted.
   void OnGridEmpty(WindowGrid* grid);
 
+  // Activates |window|.
+  void SelectWindow(aura::Window* window);
+
   bool restoring_minimized_windows() const {
     return restoring_minimized_windows_;
   }
 
   // gfx::DisplayObserver:
   void OnDisplayAdded(const gfx::Display& display) override;
   void OnDisplayRemoved(const gfx::Display& display) override;
   void OnDisplayMetricsChanged(const gfx::Display& display,
                                uint32_t metrics) override;
 
@@ skipping 84 matching lines @@
   // Tracks whether minimized windows are currently being restored for overview
   // mode.
   bool restoring_minimized_windows_;
 
   DISALLOW_COPY_AND_ASSIGN(WindowSelector);
 };
 
 }  // namespace ash
 
 #endif  // ASH_WM_OVERVIEW_WINDOW_SELECTOR_H_