Disable token handle fetching on some devices

chrome/browser/chromeos/login/existing_user_controller.cc

 // 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.
 
 #include "chrome/browser/chromeos/login/existing_user_controller.h"
 
 #include <vector>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 1218 matching lines @@
 }
 
 void ExistingUserController::OnOAuth2TokensFetched(
     bool success,
     const UserContext& user_context) {
   if (!success) {
     LOG(ERROR) << "OAuth2 token fetch failed.";
     OnAuthFailure(AuthFailure(AuthFailure::FAILED_TO_INITIALIZE_TOKEN));
     return;
   }
-  if (StartupUtils::IsWebviewSigninEnabled()) {
+  if (StartupUtils::IsWebviewSigninEnabled() && TokenHandlesEnabled()) {
     if (!token_handle_util_.get()) {
       token_handle_util_.reset(
           new TokenHandleUtil(user_manager::UserManager::Get()));
     }
     if (!token_handle_util_->HasToken(user_context.GetUserID())) {
       token_handle_util_->GetTokenHandle(
           user_context.GetUserID(), user_context.GetAccessToken(),
           base::Bind(&ExistingUserController::OnTokenHandleObtained,
                      weak_factory_.GetWeakPtr()));
     }
   }
   PerformLogin(user_context, LoginPerformer::AUTH_MODE_EXTENSION);
 }
 
 void ExistingUserController::OnTokenHandleObtained(
     const user_manager::UserID& id,
     TokenHandleUtil::TokenHandleStatus status) {
   if (status != TokenHandleUtil::VALID) {
     LOG(ERROR) << "OAuth2 token handle fetch failed.";
     return;
   }
 }
 
+bool ExistingUserController::TokenHandlesEnabled() {

[Nikita (slow), 2015/05/13 08:34:52]

I suggest having static function in TokenHandleUtil instead as this code doesn't
really belong in ExistingUserController.

+  bool ephemeral_users_enabled = false;
+  bool show_names_on_signin = true;
+  cros_settings_->GetBoolean(kAccountsPrefEphemeralUsersEnabled,
+                             &ephemeral_users_enabled);
+  cros_settings_->GetBoolean(kAccountsPrefShowUserNamesOnSignIn,
+                             &show_names_on_signin);
+  return show_names_on_signin && !ephemeral_users_enabled;
+}
+
 }  // namespace chromeos