Remove const qualifier from function return type.

ash/system/tray/default_system_tray_delegate.cc

 // Copyright 2013 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.
 
 #include "ash/system/tray/default_system_tray_delegate.h"
 
 #include <string>
 
 #include "ash/networking_config_delegate.h"
 #include "ash/session/session_state_delegate.h"
@@ skipping 12 matching lines @@
 }
 
 bool DefaultSystemTrayDelegate::GetTrayVisibilityOnStartup() {
   return true;
 }
 
 user::LoginStatus DefaultSystemTrayDelegate::GetUserLoginStatus() const {
   return user::LOGGED_IN_USER;
 }
 
-const std::string DefaultSystemTrayDelegate::GetSupervisedUserManager() const {
+std::string DefaultSystemTrayDelegate::GetSupervisedUserManager() const {
   if (!IsUserSupervised())
     return std::string();
   return "manager@chrome.com";
 }
 
 bool DefaultSystemTrayDelegate::IsUserSupervised() const {
   return GetUserLoginStatus() == ash::user::LOGGED_IN_SUPERVISED;
 }
 
 void DefaultSystemTrayDelegate::GetSystemUpdateInfo(UpdateInfo* info) const {
@@ skipping 40 matching lines @@
     scoped_ptr<VolumeControlDelegate> delegate) {
   volume_control_delegate_ = delegate.Pass();
 }
 
 int DefaultSystemTrayDelegate::GetSystemTrayMenuWidth() {
   // This is the default width for English languages.
   return 300;
 }
 
 }  // namespace ash