Update the layout mode first when exiting tablet mode

ash/common/wm_shell.h

 // Copyright 2016 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_COMMON_WM_SHELL_H_
 #define ASH_COMMON_WM_SHELL_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 350 matching lines @@
 
   // Creates the ShelfView for each display and populates it with items.
   // Called after the user session is active and profile is available.
   void CreateShelfView();
 
   void CreateShelfDelegate();
 
   // Called after maximize mode has started, windows might still animate though.
   void OnMaximizeModeStarted();
 
+  // Called after maximize mode is about to end.
+  void OnMaximizeModeEnding();
+
   // Called after maximize mode has ended, windows might still be returning to
   // their original position.
   void OnMaximizeModeEnded();
 
   // Called when the overview mode is about to be started (before the windows
   // get re-arranged).
   virtual void OnOverviewModeStarting() = 0;
 
   // Called after overview mode has ended.
   virtual void OnOverviewModeEnded() = 0;
@@ skipping 167 matching lines @@
 
   bool added_activation_observer_ = false;
   base::ObserverList<WmActivationObserver> activation_observers_;
 
   scoped_refptr<base::SequencedWorkerPool> blocking_pool_;
 };
 
 }  // namespace ash
 
 #endif  // ASH_COMMON_WM_SHELL_H_