Add MenuItemView API to add and remove items at a particular index.

views/controls/menu/menu_item_view.h

Index: views/controls/menu/menu_item_view.h
diff --git a/views/controls/menu/menu_item_view.h b/views/controls/menu/menu_item_view.h
index 308c3e20aafd0a41f63ae966a6ef89be934615d3..8ebc64e05996afd598a55ccb77650a0f91aa67bb 100644
--- a/views/controls/menu/menu_item_view.h
+++ b/views/controls/menu/menu_item_view.h
@@ -7,6 +7,7 @@
 #pragma once
 
 #include <string>
+#include <vector>
 
 #if defined(OS_WIN)
 #include <windows.h>
@@ -127,7 +128,20 @@ class MenuItemView : public View {
   // Hides and cancels the menu. This does nothing if the menu is not open.
   void Cancel();
 
-  // Adds an item to this menu.
+  // Add an item to the menu at a specified index.  ChildrenChanged() should
+  // called after adding menu items if the menu may be active.
+  MenuItemView* AddMenuItemAt(int index,
+                              int item_id,
+                              const std::wstring& label,
+                              const SkBitmap& icon,
+                              Type type);
+
+  // Remove an item from the menu at a specified index.
+  // ChildrenChanged() should be called after removing menu items (whether
+  // the menu may be active or not).
+  void RemoveMenuItemAt(int index);
+
+  // Appends an item to this menu.
   // item_id    The id of the item, used to identify it in delegate callbacks
   //            or (if delegate is NULL) to identify the command associated
   //            with this item with the controller specified in the ctor. Note
@@ -423,6 +437,9 @@ class MenuItemView : public View {
   // GetPreferredSize.
   gfx::Size pref_size_;
 
+  // Removed items to be deleted in ChildrenChanged().
+  std::vector<View*> removed_items_;
+
   DISALLOW_COPY_AND_ASSIGN(MenuItemView);
 };