Update the layout mode first when exiting tablet mode

components/exo/wm_helper.h

Index: components/exo/wm_helper.h
diff --git a/components/exo/wm_helper.h b/components/exo/wm_helper.h
index d814e5bcf9dd1d92e71ad175421684bffea1fc07..9ce432b862d28ebad0d2a0a769d7f73912e02eba 100644
--- a/components/exo/wm_helper.h
+++ b/components/exo/wm_helper.h
@@ -56,6 +56,7 @@ class WMHelper {
   class MaximizeModeObserver {
    public:
     virtual void OnMaximizeModeStarted() = 0;
+    virtual void OnMaximizeModeEnding() = 0;
     virtual void OnMaximizeModeEnded() = 0;
 
    protected:
@@ -121,6 +122,7 @@ class WMHelper {
   void NotifyCursorVisibilityChanged(bool is_visible);
   void NotifyCursorSetChanged(ui::CursorSetType cursor_set);
   void NotifyMaximizeModeStarted();
+  void NotifyMaximizeModeEnding();
   void NotifyMaximizeModeEnded();
   void NotifyAccessibilityModeChanged();
   void NotifyKeyboardDeviceConfigurationChanged();