Do all OOLing in the views code. linux_views now builds clean with the clang plugin.

views/controls/menu/menu_separator.h

 // Copyright (c) 2009 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 VIEWS_CONTROLS_MENU_MENU_SEPARATOR_H_
 #define VIEWS_CONTROLS_MENU_MENU_SEPARATOR_H_
 #pragma once
 
 #include "views/view.h"
 
 namespace views {
 
 class MenuSeparator : public View {
  public:
   MenuSeparator() {}
 
   // View overrides.
-  void OnPaint(gfx::Canvas* canvas);
-  gfx::Size GetPreferredSize();
+  virtual void OnPaint(gfx::Canvas* canvas);
+  virtual gfx::Size GetPreferredSize();
 
  private:
   DISALLOW_COPY_AND_ASSIGN(MenuSeparator);
 };
 
 }  // namespace views
 
 #endif  // VIEWS_CONTROLS_MENU_MENU_SEPARATOR_H_