Wait for Cryptohome service to be available on login.

chrome/browser/chromeos/login/existing_user_controller.h

 // 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.
 
 #ifndef CHROME_BROWSER_CHROMEOS_LOGIN_EXISTING_USER_CONTROLLER_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_EXISTING_USER_CONTROLLER_H_
 
 #include <stddef.h>
 
 #include <memory>
@@ skipping 233 matching lines @@
   void LoginAsPublicSessionInternal(const UserContext& user_context);
 
   // Performs sets of actions right prior to login has been started.
   void PerformPreLoginActions(const UserContext& user_context);
 
   // Performs set of actions when login has been completed or has been
   // cancelled. If |start_auto_login_timer| is true than
   // auto-login timer is started.
   void PerformLoginFinishedActions(bool start_auto_login_timer);
 
+  // Invokes |continuation| after verifying that cryptohome service is available
+  void ContinueLoginWhenCryptohomeAvailable(
+      const base::OnceClosure continuation,

[xiyuan, 2017/04/18 16:38:00]

This could not be "const" since we would std::move() it, right? At least, it
should be consistent with cc file.

[Sergey Poromov, 2017/04/19 11:08:25]

Done.

+      bool service_is_available);
+
   // Invokes |continuation| after verifying that the device is not disabled.
   void ContinueLoginIfDeviceNotDisabled(const base::Closure& continuation);
 
   // Signs in as a new user. This is a continuation of CompleteLogin() that gets
   // invoked after it has been verified that the device is not disabled.
   void DoCompleteLogin(const UserContext& user_context);
 
   // Signs in as a known user. This is a continuation of Login() that gets
   // invoked after it has been verified that the device is not disabled.
   void DoLogin(const UserContext& user_context,
@@ skipping 123 matching lines @@
 
   // Factory of callbacks.
   base::WeakPtrFactory<ExistingUserController> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ExistingUserController);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_EXISTING_USER_CONTROLLER_H_