Move Singleton and related structs to namespace base

ui/views/focus/view_storage.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef UI_VIEWS_FOCUS_VIEW_STORAGE_H_
 #define UI_VIEWS_FOCUS_VIEW_STORAGE_H_
 
 #include <map>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "ui/views/views_export.h"
 
+namespace base {
 template <typename T> struct DefaultSingletonTraits;
+}
 
 // This class is a simple storage place for storing/retrieving views.  It is
 // used for example in the FocusManager to store/restore focused views when the
 // main window becomes active/inactive.
 // It automatically removes a view from the storage if the view is removed from
 // the tree hierarchy or when the view is destroyed, which ever comes first.
 //
 // To use it, you first need to create a view storage id that can then be used
 // to store/retrieve views.
 
@@ skipping 17 matching lines @@
 
   // Removes the view associated with |storage_id| if any.
   void RemoveView(int storage_id);
 
   // Notifies the ViewStorage that a view was removed from its parent somewhere.
   void ViewRemoved(View* removed);
 
   size_t view_count() const { return view_to_ids_.size(); }
 
  private:
-  friend struct DefaultSingletonTraits<ViewStorage>;
+  friend struct base::DefaultSingletonTraits<ViewStorage>;
 
   ViewStorage();
   ~ViewStorage();
 
   // Removes the view associated with |storage_id|. If |remove_all_ids| is true,
   // all other mapping pointing to the same view are removed as well.
   void EraseView(int storage_id, bool remove_all_ids);
 
   // Next id for the view storage.
   int view_storage_next_id_;
 
   // The association id to View used for the view storage.
   std::map<int, View*> id_to_view_;
 
   // Association View to id, used to speed up view notification removal.
   std::map<View*, std::vector<int>*> view_to_ids_;
 
   DISALLOW_COPY_AND_ASSIGN(ViewStorage);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_FOCUS_VIEW_STORAGE_H_