Update app list search box menu when Users changes

ui/app_list/app_list_view_delegate.h

Index: ui/app_list/app_list_view_delegate.h
diff --git a/ui/app_list/app_list_view_delegate.h b/ui/app_list/app_list_view_delegate.h
index 4da51a67ee6384eaf72e0c08d0e2ce47b4af2744..fb98a736f8e1925075e5ed7513b204d027d22db5 100644
--- a/ui/app_list/app_list_view_delegate.h
+++ b/ui/app_list/app_list_view_delegate.h
@@ -10,6 +10,7 @@
 
 #include "base/callback_forward.h"
 #include "base/files/file_path.h"
+#include "base/observer_list.h"
 #include "base/strings/string16.h"
 #include "ui/app_list/app_list_export.h"
 
@@ -29,6 +30,7 @@ namespace app_list {
 
 class AppListItemModel;
 class AppListModel;
+class AppListViewDelegateObserver;
 class SearchResult;
 class SigninDelegate;
 
@@ -53,6 +55,8 @@ class APP_LIST_EXPORT AppListViewDelegate {
   };
   typedef std::vector<User> Users;
 
+  AppListViewDelegate() {}

[tapted, 2013/11/22 00:03:19]

heads-up clang will probably complain about this and the destructor not having a
separate definition in the .cc (but maybe moot anyway)

+
   // AppListView owns the delegate.
   virtual ~AppListViewDelegate() {}
 
@@ -123,7 +127,19 @@ class APP_LIST_EXPORT AppListViewDelegate {
   virtual content::WebContents* GetStartPageContents() = 0;
 
   // Returns the list of users (for AppListMenu).
-  virtual const Users& GetUsers() const = 0;
+  const Users& GetUsers() const;
+
+  void AddObserver(AppListViewDelegateObserver* observer);
+  void RemoveObserver(AppListViewDelegateObserver* observer);
+
+ protected:
+  void NotifyUsersChanged();
+
+  Users users_;
+  ObserverList<AppListViewDelegateObserver> observers_;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(AppListViewDelegate);
 };
 
 }  // namespace app_list