Replace string16 with base::string16.

chrome/browser/chromeos/options/passphrase_textfield.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/chromeos/options/passphrase_textfield.h"
 
 #include "base/strings/utf_string_conversions.h"
 
 namespace chromeos {
 
@@ skipping 23 matching lines @@
   if (show_fake_ && text().empty())
     SetFakePassphrase();
   Textfield::OnBlur();
 }
 
 std::string PassphraseTextfield::GetPassphrase() {
   return changed_ ? UTF16ToUTF8(text()) : std::string();
 }
 
 void PassphraseTextfield::SetFakePassphrase() {
-  CR_DEFINE_STATIC_LOCAL(string16, fake_passphrase, (ASCIIToUTF16("********")));
+  CR_DEFINE_STATIC_LOCAL(base::string16, fake_passphrase,
+      (ASCIIToUTF16("********")));
   SetText(fake_passphrase);
   changed_ = false;
 }
 
 void PassphraseTextfield::ClearFakePassphrase() {
-  SetText(string16());
+  SetText(base::string16());
   changed_ = true;
 }
 
 }  // namespace chromeos