Convert string16 to base::string16 in content.

content/shell/geolocation/shell_access_token_store.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 "content/shell/geolocation/shell_access_token_store.h"
 
 #include "base/bind.h"
 #include "base/message_loop/message_loop.h"
 #include "base/strings/utf_string_conversions.h"
 #include "content/public/browser/browser_thread.h"
@@ skipping 31 matching lines @@
 void ShellAccessTokenStore::RespondOnOriginatingThread(
     const LoadAccessTokensCallbackType& callback) {
   // Since content_shell is a test executable, rather than an end user program,
   // we provide a dummy access_token set to avoid hitting the server.
   AccessTokenSet access_token_set;
   access_token_set[GURL()] = ASCIIToUTF16("chromium_content_shell");
   callback.Run(access_token_set, system_request_context_);
 }
 
 void ShellAccessTokenStore::SaveAccessToken(
-    const GURL& server_url, const string16& access_token) {
+    const GURL& server_url, const base::string16& access_token) {
 }
 
 }  // namespace content