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..47d0b4e7521caa8d420f752179cfff20f39a66d2 100644
--- a/ui/views/controls/menu/menu_item_view.cc
+++ b/ui/views/controls/menu/menu_item_view.cc
@@ -110,6 +110,8 @@ MenuItemView::MenuItemView(MenuDelegate* delegate)
       use_right_margin_(true) {
   // NOTE: don't check the delegate for NULL, UpdateMenuPartSizes() supplies a
   // NULL delegate.
+  // Note: This class also has a protected constructor and a common Init
+  // function to initialize both.

[Finnur, 2014/02/13 10:19:43]

I was hoping to see this comment on line 91 (above the constructor) because
other people are going to make the same mistake we did. Find the first
constructor in the file, add their variable to it and call it a day (totally
missing the other constructor).

   Init(NULL, 0, SUBMENU, delegate);
 }
 
@@ -581,12 +583,16 @@ MenuItemView::MenuItemView(MenuItemView* parent,
       requested_menu_position_(POSITION_BEST_FIT),
       actual_menu_position_(requested_menu_position_),
       use_right_margin_(true) {
+  // Note: This class also has a public constructor and a common Init function
+  // to initialize both.

[Finnur, 2014/02/13 10:19:43]

Same here, move to line 564.

   Init(parent, command, type, NULL);
 }
 
 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.