Use callbacks in SessionRestore unit tests

chrome/chrome_tests_unit.gypi

 # Copyright 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.
 {
   'variables': {
     'chrome_unit_tests_sources': [
       '../components/autofill/content/renderer/test_password_autofill_agent.cc',
       '../components/autofill/content/renderer/test_password_autofill_agent.h',
       '../components/autofill/content/renderer/test_password_generation_agent.cc',
       '../components/autofill/content/renderer/test_password_generation_agent.h',
@@ skipping 1632 matching lines @@
         'browser/password_manager/test_password_store_service.cc',
         'browser/password_manager/test_password_store_service.h',
         'browser/prefs/pref_service_mock_factory.cc',
         'browser/prefs/pref_service_mock_factory.h',
         'browser/profile_resetter/profile_resetter_test_base.cc',
         'browser/profile_resetter/profile_resetter_test_base.h',
         'browser/search_engines/template_url_service_factory_test_util.cc',
         'browser/search_engines/template_url_service_factory_test_util.h',
         'browser/search_engines/template_url_service_test_util.cc',
         'browser/search_engines/template_url_service_test_util.h',
+        'browser/sessions/session_restore_test_helper.cc',
+        'browser/sessions/session_restore_test_helper.h',
         'browser/sessions/session_service_test_helper.cc',
         'browser/sessions/session_service_test_helper.h',
         'browser/signin/fake_account_reconcilor.cc',
         'browser/signin/fake_account_reconcilor.h',
         'browser/signin/fake_account_tracker_service.cc',
         'browser/signin/fake_account_tracker_service.h',
         'browser/signin/fake_profile_oauth2_token_service.cc',
         'browser/signin/fake_profile_oauth2_token_service.h',
         'browser/signin/fake_profile_oauth2_token_service_builder.cc',
         'browser/signin/fake_profile_oauth2_token_service_builder.h',
@@ skipping 1084 matching lines @@
               'dependencies': [
                 '../tools/xdisplaycheck/xdisplaycheck.gyp:xdisplaycheck',
               ],
             }],
           ],
         },
       ],
     }],
   ],  # 'conditions'
 }