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

ui/views/controls/menu/menu_item_view.cc

Index: ui/views/controls/menu/menu_item_view.cc
diff --git a/ui/views/controls/menu/menu_item_view.cc b/ui/views/controls/menu/menu_item_view.cc
index 15e7db39e64f632c32e0b4c4dd29f646515b5a0f..42f41afdaab07fdf03044a6946ab7505e80a967e 100644
--- a/ui/views/controls/menu/menu_item_view.cc
+++ b/ui/views/controls/menu/menu_item_view.cc
@@ -88,6 +88,8 @@ int MenuItemView::pref_menu_height_;
 // static
 const char MenuItemView::kViewClassName[] = "MenuItemView";
 
+// Note: This class also has a protected constructor and a common Init function
+// to initialize both.
 MenuItemView::MenuItemView(MenuDelegate* delegate)
     : delegate_(delegate),
       controller_(NULL),
@@ -559,6 +561,8 @@ const MenuConfig& MenuItemView::GetMenuConfig() const {
   return MenuConfig::instance(NULL);
 }
 
+// Note: This class also has a public constructor and a common Init function
+// to initialize both.
 MenuItemView::MenuItemView(MenuItemView* parent,
                            int command,
                            MenuItemView::Type type)
@@ -587,6 +591,8 @@ MenuItemView::MenuItemView(MenuItemView* parent,
 MenuItemView::~MenuItemView() {
   delete submenu_;
   STLDeleteElements(&removed_items_);
+  if (lifecycle_observer_)
+    lifecycle_observer_->OnDeleted(this);
 }
 
 const char* MenuItemView::GetClassName() const {
@@ -641,6 +647,7 @@ void MenuItemView::Init(MenuItemView* parent,
   // Assign our ID, this allows SubmenuItemView to find MenuItemViews.
   set_id(kMenuItemViewID);
   has_icons_ = false;
+  lifecycle_observer_ = NULL;
 
   // Don't request enabled status from the root menu item as it is just
   // a container for real items.  EMPTY items will be disabled.