Attempting to reland the Overview Button Change.

ash/shell_observer.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 ASH_SHELL_OBSERVER_H_
 #define ASH_SHELL_OBSERVER_H_
 
 #include "ash/ash_export.h"
 #include "ash/system/user/login_status.h"
 
@@ skipping 29 matching lines @@
                                         aura::Window* root_window) {}
 
   // Called when the overview mode is about to be started (before the windows
   // get re-arranged).
   virtual void OnOverviewModeStarting() {}
 
   // Called before the overview mode is ending (before the windows get arranged
   // to their final position).
   virtual void OnOverviewModeEnding() {}
 
+  // Called when the always maximize mode has started. Windows might still
+  // animate though.
+  virtual void OnMaximizeModeStarted() {}
+
+  // Called when the always maximize mode has ended. Windows may still be
+  // animating but have been restored.
+  virtual void OnMaximizeModeEnded() {}
+
  protected:
   virtual ~ShellObserver() {}
 };
 
 }  // namespace ash
 
 #endif  // ASH_SHELL_OBSERVER_H_