Do not send the OnWindowShowTypeChanged() notification if the show type has not changed

ash/wm/window_state.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_WINDOW_STATE_H_
 #define ASH_WM_WINDOW_STATE_H_
 
 #include "ash/ash_export.h"
 #include "ash/wm/wm_types.h"
 #include "base/basictypes.h"
@@ skipping 236 matching lines @@
   // aura::WindowObserver overrides:
   virtual void OnWindowPropertyChanged(aura::Window* window,
                                        const void* key,
                                        intptr_t old) OVERRIDE;
 
  private:
   // Snaps the window to left or right of the desktop with given bounds.
   void SnapWindow(WindowShowType left_or_right,
                   const gfx::Rect& bounds);
 
+  // Sets the window show type and updates the show state if necessary.
+  void SetWindowShowType(WindowShowType new_window_show_type);
+
   // The owner of this window settings.
   aura::Window* window_;
   scoped_ptr<WindowStateDelegate> delegate_;
 
   bool window_position_managed_;
   bool bounds_changed_by_user_;
   bool panel_attached_;
   bool continue_drag_after_reparent_;
   bool ignored_by_shelf_;
   bool can_consume_system_keys_;
   bool top_row_keys_are_function_keys_;
   WindowResizer* window_resizer_;
 
   bool always_restores_to_restore_bounds_;
   bool hide_shelf_when_fullscreen_;
   bool animate_to_fullscreen_;
   bool minimum_visibility_;
 
   // A property to remember the window position which was set before the
   // auto window position manager changed the window bounds, so that it can get
   // restored when only this one window gets shown.
   scoped_ptr<gfx::Rect> pre_auto_manage_window_bounds_;
 
   ObserverList<WindowStateObserver> observer_list_;
 
+  // True when in SetWindowShowType(). This is used to avoid reentrance.
+  bool in_set_window_show_type_;
+
   WindowShowType window_show_type_;
 
   DISALLOW_COPY_AND_ASSIGN(WindowState);
 };
 
 // Returns the WindowState for active window. Returns |NULL|
 // if there is no active window.
 ASH_EXPORT WindowState* GetActiveWindowState();
 
 // Returns the WindowState for |window|. Creates WindowState
 // if it didn't exist. The settings object is owned by |window|.
 ASH_EXPORT WindowState* GetWindowState(aura::Window* window);
 
 // const version of GetWindowState.
 ASH_EXPORT const WindowState*
 GetWindowState(const aura::Window* window);
 
 }  // namespace wm
 }  // namespace ash
 
 #endif  // ASH_WM_WINDOW_STATE_H_