Make URLDataSource::GetSource() const.

chrome/browser/ui/webui/options/chromeos/user_image_source.cc

 // 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.
 
 #include "chrome/browser/ui/webui/options/chromeos/user_image_source.h"
 
 #include "base/memory/ref_counted_memory.h"
 #include "base/message_loop.h"
 #include "base/strings/string_split.h"
 #include "chrome/browser/chromeos/login/default_user_images.h"
@@ skipping 63 matching lines @@
   }
   return ResourceBundle::GetSharedInstance().
       LoadDataResourceBytesForScale(IDR_LOGIN_DEFAULT_USER, scale_factor);
 }
 
 UserImageSource::UserImageSource() {
 }
 
 UserImageSource::~UserImageSource() {}
 
-std::string UserImageSource::GetSource() {
+std::string UserImageSource::GetSource() const {
   return chrome::kChromeUIUserImageHost;
 }
 
 void UserImageSource::StartDataRequest(
     const std::string& path,
     bool is_incognito,
     const content::URLDataSource::GotDataCallback& callback) {
   std::string email;
   bool is_image_animated = false;
   ui::ScaleFactor scale_factor;
@@ skipping 15 matching lines @@
   if (is_image_animated) {
     const chromeos::User* user = chromeos::UserManager::Get()->FindUser(email);
     if (user && user->has_animated_image())
       return "image/gif";
   }
   return "image/png";
 }
 
 }  // namespace options
 }  // namespace chromeos