Update the layout mode first when exiting tablet mode

components/exo/wm_helper.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 COMPONENTS_EXO_WM_HELPER_H_
 #define COMPONENTS_EXO_WM_HELPER_H_
 
 #include "base/macros.h"
 #include "base/observer_list.h"
 #include "ui/base/cursor/cursor.h"
@@ skipping 38 matching lines @@
     virtual void OnCursorVisibilityChanged(bool is_visible) {}
     virtual void OnCursorSetChanged(ui::CursorSetType cursor_set) {}
 
    protected:
     virtual ~CursorObserver() {}
   };
 
   class MaximizeModeObserver {
    public:
     virtual void OnMaximizeModeStarted() = 0;
+    virtual void OnMaximizeModeEnding() = 0;
     virtual void OnMaximizeModeEnded() = 0;
 
    protected:
     virtual ~MaximizeModeObserver() {}
   };
 
   class AccessibilityObserver {
    public:
     virtual void OnAccessibilityModeChanged() = 0;
 
@@ skipping 45 matching lines @@
  protected:
   WMHelper();
 
   void NotifyWindowActivated(aura::Window* gained_active,
                              aura::Window* lost_active);
   void NotifyWindowFocused(aura::Window* gained_focus,
                            aura::Window* lost_focus);
   void NotifyCursorVisibilityChanged(bool is_visible);
   void NotifyCursorSetChanged(ui::CursorSetType cursor_set);
   void NotifyMaximizeModeStarted();
+  void NotifyMaximizeModeEnding();
   void NotifyMaximizeModeEnded();
   void NotifyAccessibilityModeChanged();
   void NotifyKeyboardDeviceConfigurationChanged();
 
  private:
   base::ObserverList<ActivationObserver> activation_observers_;
   base::ObserverList<FocusObserver> focus_observers_;
   base::ObserverList<CursorObserver> cursor_observers_;
   base::ObserverList<MaximizeModeObserver> maximize_mode_observers_;
   base::ObserverList<AccessibilityObserver> accessibility_observers_;
   base::ObserverList<InputDeviceEventObserver> input_device_event_observers_;
 
   DISALLOW_COPY_AND_ASSIGN(WMHelper);
 };
 
 }  // namespace exo
 
 #endif  // COMPONENTS_EXO_WM_HELPER_H_