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

chrome/browser/chromeos/policy/power_policy_browsertest.cc

 // Copyright (c) 2013 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 <stdint.h>
 
 #include <string>
 #include <vector>
 
 #include "base/bind.h"
@@ skipping 188 matching lines @@
   InstallUserKey();
   user_policy_.policy_data().set_username(
       chromeos::login::StubAccountId().GetUserEmail());
 }
 
 void PowerPolicyBrowserTestBase::InstallUserKey() {
   base::FilePath user_keys_dir;
   ASSERT_TRUE(PathService::Get(chromeos::DIR_USER_POLICY_KEYS, &user_keys_dir));
   std::string sanitized_username =
       chromeos::CryptohomeClient::GetStubSanitizedUsername(
-          chromeos::login::StubAccountId().GetUserEmail());
+          cryptohome::Identification(chromeos::login::StubAccountId()));
   base::FilePath user_key_file =
       user_keys_dir.AppendASCII(sanitized_username)
                    .AppendASCII("policy.pub");
   std::vector<uint8_t> user_key_bits;
   ASSERT_TRUE(user_policy_.GetSigningKey()->ExportPublicKey(&user_key_bits));
   ASSERT_TRUE(base::CreateDirectory(user_key_file.DirName()));
   ASSERT_EQ(base::WriteFile(
                 user_key_file,
                 reinterpret_cast<const char*>(user_key_bits.data()),
                 user_key_bits.size()),
             static_cast<int>(user_key_bits.size()));
 }
 
 void PowerPolicyBrowserTestBase::StoreAndReloadUserPolicy() {
   // Install the new user policy blob in session manager client.
   user_policy_.Build();
   session_manager_client()->set_user_policy(
-      user_policy_.policy_data().username(),
+      cryptohome::Identification(
+          AccountId::FromUserEmail(user_policy_.policy_data().username())),
       user_policy_.GetBlob());
 
   // Reload user policy from session manager client and wait for the update to
   // take effect.
   RunClosureAndWaitForUserPolicyUpdate(
       base::Bind(&PowerPolicyBrowserTestBase::ReloadUserPolicy, this,
                  browser()->profile()),
       browser()->profile());
 }
 
@@ skipping 273 matching lines @@
   policy = baseline_policy;
   policy.set_ac_idle_action(power_manager_client_->policy().ac_idle_action());
   policy.set_battery_idle_action(
       power_manager_client_->policy().battery_idle_action());
   policy.set_reason(power_manager_client_->policy().reason());
   EXPECT_EQ(GetDebugString(policy),
             GetDebugString(power_manager_client_->policy()));
 }
 
 }  // namespace policy