Prefix string16 with base:: in ui/.

ui/views/views_delegate.h

Index: ui/views/views_delegate.h
diff --git a/ui/views/views_delegate.h b/ui/views/views_delegate.h
index 8227865ef3677ce2d5eee220ed104d7ee3b227d5..9ae48eecd3f2913786b456b1a916c39d3b273542 100644
--- a/ui/views/views_delegate.h
+++ b/ui/views/views_delegate.h
@@ -80,8 +80,8 @@ class VIEWS_EXPORT ViewsDelegate {
 
   // For accessibility, notify the delegate that a menu item was focused
   // so that alternate feedback (speech / magnified text) can be provided.
-  virtual void NotifyMenuItemFocused(const string16& menu_name,
-                                     const string16& menu_item_name,
+  virtual void NotifyMenuItemFocused(const base::string16& menu_name,
+                                     const base::string16& menu_item_name,
                                      int item_index,
                                      int item_count,
                                      bool has_submenu) = 0;