Fix the clang bot.

chrome/browser/chromeos/login/mock_authenticator.cc

Index: chrome/browser/chromeos/login/mock_authenticator.cc
diff --git a/chrome/browser/chromeos/login/mock_authenticator.cc b/chrome/browser/chromeos/login/mock_authenticator.cc
index 0eac19f503055f544175e20742622e46aa01ffa4..ab042ca7ea021b92aa5a25d098005d3092edc57f 100644
--- a/chrome/browser/chromeos/login/mock_authenticator.cc
+++ b/chrome/browser/chromeos/login/mock_authenticator.cc
@@ -60,6 +60,15 @@ void MockAuthenticator::OnLoginFailure(const LoginFailure& failure) {
         BrowserThread::UI, FROM_HERE, new MessageLoop::QuitTask);
 }
 
+std::string MockAuthenticator::EncryptToken(const std::string& token) {
+  return std::string();
+}
+
+std::string MockAuthenticator::DecryptToken(
+    const std::string& encrypted_token) {
+  return std::string();
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // MockLoginUtils