ChromeOS cryptohome should be able to use gaia id as user identifier.

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

 // 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.
 
 #include "chrome/browser/chromeos/login/users/chrome_user_manager_impl.h"
 
 #include <stddef.h>
 #include <cstddef>
 #include <set>
 #include <utility>
@@ skipping 588 matching lines @@
 
 void ChromeUserManagerImpl::PerformPostUserLoggedInActions(
     bool browser_restart) {
   // Initialize the session length limiter and start it only if
   // session limit is defined by the policy.
   session_length_limiter_.reset(
       new SessionLengthLimiter(NULL, browser_restart));
 }
 
 bool ChromeUserManagerImpl::IsDemoApp(const AccountId& account_id) const {
-  return DemoAppLauncher::IsDemoAppSession(account_id.GetUserEmail());
+  return DemoAppLauncher::IsDemoAppSession(account_id);
 }
 
 bool ChromeUserManagerImpl::IsKioskApp(const AccountId& account_id) const {
   policy::DeviceLocalAccount::Type device_local_account_type;
   return policy::IsDeviceLocalAccountUser(account_id.GetUserEmail(),
                                           &device_local_account_type) &&
          device_local_account_type ==
              policy::DeviceLocalAccount::TYPE_KIOSK_APP;
 }
 
@@ skipping 624 matching lines @@
 }
 
 bool ChromeUserManagerImpl::IsFirstExecAfterBoot() const {
   return base::CommandLine::ForCurrentProcess()->HasSwitch(
       chromeos::switches::kFirstExecAfterBoot);
 }
 
 void ChromeUserManagerImpl::AsyncRemoveCryptohome(
     const AccountId& account_id) const {
   cryptohome::AsyncMethodCaller::GetInstance()->AsyncRemove(
-      account_id.GetUserEmail(), base::Bind(&OnRemoveUserComplete, account_id));
+      cryptohome::Identification(account_id),
+      base::Bind(&OnRemoveUserComplete, account_id));
 }
 
 bool ChromeUserManagerImpl::IsGuestAccountId(
     const AccountId& account_id) const {
   return account_id == login::GuestAccountId();
 }
 
 bool ChromeUserManagerImpl::IsStubAccountId(const AccountId& account_id) const {
   return account_id == login::StubAccountId();
 }
@@ skipping 29 matching lines @@
       base::Bind(ResolveLocale, locale, base::Unretained(out_resolved_locale)),
       on_resolved_callback);
 }
 
 bool ChromeUserManagerImpl::IsValidDefaultUserImageId(int image_index) const {
   return image_index >= 0 &&
          image_index < chromeos::default_user_image::kDefaultImagesCount;
 }
 
 }  // namespace chromeos