Handle app custom icon via aura::Window property.

chrome/browser/ui/ash/launcher/app_window_launcher_item_controller.h

 // Copyright 2014 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 CHROME_BROWSER_UI_ASH_LAUNCHER_APP_WINDOW_LAUNCHER_ITEM_CONTROLLER_H_
 #define CHROME_BROWSER_UI_ASH_LAUNCHER_APP_WINDOW_LAUNCHER_ITEM_CONTROLLER_H_
 
 #include <list>
 #include <string>
 
@@ skipping 42 matching lines @@
   void OnWindowPropertyChanged(aura::Window* window,
                                const void* key,
                                intptr_t old) override;
 
   // Get the number of running applications/incarnations of this.
   size_t window_count() const { return windows_.size(); }
 
   // Activates the window at position |index|.
   void ActivateIndexedApp(size_t index);
 
-  // Called when launcher item may need to be updated, eg. label or icon.
-  // TODO(khmel): Use aura::Window property and observe property change
-  // http://crbug.com/724292
-  virtual void UpdateLauncherItem() {}
-
   const WindowList& windows() const { return windows_; }
 
  protected:
   explicit AppWindowLauncherItemController(const ash::ShelfID& shelf_id);
 
   // Returns the action performed. Should be one of SHELF_ACTION_NONE,
   // SHELF_ACTION_WINDOW_ACTIVATED, or SHELF_ACTION_WINDOW_MINIMIZED.
   ash::ShelfAction ShowAndActivateOrMinimize(ui::BaseWindow* window);
 
   // Activate the given |window_to_show|, or - if already selected - advance to
   // the next window of similar type.
   // Returns the action performed. Should be one of SHELF_ACTION_NONE,
   // SHELF_ACTION_WINDOW_ACTIVATED, or SHELF_ACTION_WINDOW_MINIMIZED.
   ash::ShelfAction ActivateOrAdvanceToNextAppWindow(
       ui::BaseWindow* window_to_show);
 
   // Returns last active window in the controller or first window.
   ui::BaseWindow* GetLastActiveWindow();
 
  private:
   WindowList::iterator GetFromNativeWindow(aura::Window* window);
 
+  // Handles the case when the app window in this controller has been changed,
+  // and sets the new controller icon based on the currently active window.
+  void UpdateShelfItemIcon();
+
   // List of associated app windows
   WindowList windows_;
 
   // Pointer to the most recently active app window
   // TODO(khmel): Get rid of |last_active_window_| and provide more reliable
   // way to determine active window.
   ui::BaseWindow* last_active_window_ = nullptr;
 
   // Scoped list of observed windows (for removal on destruction)
   ScopedObserver<aura::Window, aura::WindowObserver> observed_windows_;
 
   DISALLOW_COPY_AND_ASSIGN(AppWindowLauncherItemController);
 };
 
 #endif  // CHROME_BROWSER_UI_ASH_LAUNCHER_APP_WINDOW_LAUNCHER_ITEM_CONTROLLER_H_