Add notification mechanism when BrowserActionButton's icon has been updated.

ui/views/controls/menu/menu_item_view.h

 // Copyright (c) 2012 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 UI_VIEWS_CONTROLS_MENU_MENU_ITEM_VIEW_H_
 #define UI_VIEWS_CONTROLS_MENU_MENU_ITEM_VIEW_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 43 matching lines @@
 // activated by way of space/return keys. Activating a focusable child results
 // in |AcceleratorPressed| being invoked. Note, that as menus try not to steal
 // focus from the hosting window child views do not actually get focus. Instead
 // |SetHotTracked| is used as the user navigates around.
 //
 // To show the menu use MenuRunner. See MenuRunner for details on how to run
 // (show) the menu as well as for details on the life time of the menu.
 
 class VIEWS_EXPORT MenuItemView : public View {
  public:
+  // The LifecycleObserver will receive a notification when the MenuItemView has
+  // been deleted.
+  class LifecycleObserver {
+   public:
+    virtual ~LifecycleObserver() {}
+    virtual void OnDeleted(MenuItemView* view) = 0;
+  };
+
+  void set_lifecycle_observer(LifecycleObserver* lifecycle_observer) {
+    lifecycle_observer_ = lifecycle_observer;
+  }
+
   friend class MenuController;
 
   // The menu item view's class name.
   static const char kViewClassName[];
 
   // ID used to identify menu items.
   static const int kMenuItemViewID;
 
   // ID used to identify empty menu items.
   static const int kEmptyMenuItemViewID;
@@ skipping 445 matching lines @@
   // |menu_position_| is the requested position with respect to the bounds.
   // |actual_menu_position_| is used by the controller to cache the
   // position of the menu being shown.
   MenuPosition requested_menu_position_;
   MenuPosition actual_menu_position_;
 
   // If set to false, the right margin will be removed for menu lines
   // containing other elements.
   bool use_right_margin_;
 
+  LifecycleObserver* lifecycle_observer_;

[Finnur, 2014/02/10 10:41:41]

nit: Document.

+
   DISALLOW_COPY_AND_ASSIGN(MenuItemView);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_CONTROLS_MENU_MENU_ITEM_VIEW_H_