This CL replaces e-mail with AccountId in easy signin code.

chrome/browser/chromeos/login/supervised/supervised_user_creation_controller_new.h

 // Copyright 2014 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_SUPERVISED_SUPERVISED_USER_CREATION_CONTROLLER_NEW_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_SUPERVISED_SUPERVISED_USER_CREATION_CONTROLLER_NEW_H_
 
 #include <string>
 
 #include "base/files/file_path.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/strings/string16.h"
 #include "base/timer/timer.h"
 #include "base/values.h"
 #include "chrome/browser/chromeos/login/supervised/supervised_user_creation_controller.h"
 #include "chrome/browser/supervised_user/legacy/supervised_user_registration_utility.h"
 #include "chromeos/login/auth/extended_authenticator.h"
+#include "components/signin/core/account_id/account_id.h"
 
 class Profile;
 
 namespace chromeos {
 
 class UserContext;
 
 // Supervised user creation process:
 // 0. Manager is logged in
 // 1. Generate ID for new supervised user
 // 2. Start "transaction" in Local State.
 // 3, Generate keys for user : master key, salt, encryption and signature keys.
 // 4. Create local cryptohome (errors could arise)
 // 5. Create user in cloud (errors could arise)
 // 6. Store cloud token in cryptohome (actually, error could arise).
 // 7. Mark "transaction" as completed.
 // 8. End manager session.
 class SupervisedUserCreationControllerNew
     : public SupervisedUserCreationController,
       public ExtendedAuthenticator::NewAuthStatusConsumer {
  public:
   // All UI initialization is deferred till Init() call.
   // |Consumer| is not owned by controller, and it is expected that it wouldn't
   // be deleted before SupervisedUserCreationControllerNew.
   SupervisedUserCreationControllerNew(StatusConsumer* consumer,
-                                      const std::string& manager_id);
+                                      const AccountId& manager_id);
   ~SupervisedUserCreationControllerNew() override;
 
   // Returns the current supervised user controller if it has been created.
   static SupervisedUserCreationControllerNew* current_controller() {
     return current_controller_;
   }
 
   // Set up controller for creating new supervised user with |display_name|,
   // |password| and avatar indexed by |avatar_index|. StartCreation() have to
   // be called to actually start creating user.
@@ skipping 57 matching lines @@
   enum CreationType { NEW_USER, USER_IMPORT_OLD, USER_IMPORT_NEW, };
 
   // Contains information necessary for new user creation.
   struct UserCreationContext {
     UserCreationContext();
     ~UserCreationContext();
 
     base::string16 display_name;
     int avatar_index;
 
-    std::string manager_id;
+    AccountId manager_id = EmptyAccountId();

[achuithb, 2015/12/04 10:12:52]

Why do this? the default ctor does the right thing, right?

[Alexander Alekseev, 2015/12/04 12:44:06]

We cannot make AccountId default-constructible until migration is done.
The purpose is to annotate all places, where we might have empty account id
objects.

 
     std::string local_user_id;  // Used to identify cryptohome.
     std::string sync_user_id;   // Used to identify user in manager's sync data.
 
     // Keys:
     std::string master_key;       // Random string
     std::string signature_key;    // 256 bit HMAC key
     std::string encryption_key;   // 256 bit HMAC key
     std::string salted_password;  // Hash(salt + Hash(password))
 
@@ skipping 50 matching lines @@
 
   // Factory of callbacks.
   base::WeakPtrFactory<SupervisedUserCreationControllerNew> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(SupervisedUserCreationControllerNew);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_SUPERVISED_SUPERVISED_USER_CREATION_CONTROLLER_NEW_H_