Fix build when ENABLE_MANAGED_USERS is not defined

chrome/browser/supervised_user/supervised_user_theme.h

 // Copyright 2014 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 CHROME_BROWSER_SUPERVISED_USER_SUPERVISED_USER_THEME_H_
 #define CHROME_BROWSER_SUPERVISED_USER_SUPERVISED_USER_THEME_H_
 
+#include "chrome/browser/supervised_user/supervised_users.h"
 #include "chrome/browser/themes/custom_theme_supplier.h"
 
 namespace gfx {
 class Image;
 }
 
 // This theme is used as a default theme for supervised users. It uses a light
 // blue as frame color, and defines color properties for the avatar label.
 class SupervisedUserTheme : public CustomThemeSupplier {
  public:
   SupervisedUserTheme();
 
   // Overridden from CustomThemeSupplier:
   virtual bool GetColor(int id, SkColor* color) const OVERRIDE;
   virtual gfx::Image GetImageNamed(int id) OVERRIDE;
   virtual bool HasCustomImage(int id) const OVERRIDE;
 
  private:
   virtual ~SupervisedUserTheme();
 
   DISALLOW_COPY_AND_ASSIGN(SupervisedUserTheme);
 };
 
 #endif  // CHROME_BROWSER_SUPERVISED_USER_SUPERVISED_USER_THEME_H_