Implement oauth token external handler checking.

chrome/browser/chromeos/login/users/fake_chrome_user_manager.cc

 // Copyright 2015 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/login/users/fake_chrome_user_manager.h"
 
 #include "chrome/browser/chromeos/login/users/chrome_user_manager.h"
 #include "chrome/browser/chromeos/login/users/fake_supervised_user_manager.h"
 #include "chrome/browser/chromeos/profiles/profile_helper.h"
 #include "chrome/browser/chromeos/settings/cros_settings.h"
@@ skipping 155 matching lines @@
 
   return result;
 }
 
 UserFlow* FakeChromeUserManager::GetDefaultUserFlow() const {
   if (!default_flow_.get())
     default_flow_.reset(new DefaultUserFlow());
   return default_flow_.get();
 }
 
+bool FakeChromeUserManager::FindKnownUserPrefs(
+    const user_manager::UserID& user_id,
+    const base::DictionaryValue** out_value) {
+  return false;
+}
+
+void FakeChromeUserManager::UpdateKnownUserPrefs(
+    const user_manager::UserID& user_id,
+    const base::DictionaryValue& values,
+    bool clear) {
+}
+
 }  // namespace chromeos