Use ScopedTaskEnvironment instead of MessageLoop in components unit tests.

components/invalidation/impl/invalidation_notifier_unittest.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 "components/invalidation/impl/invalidation_notifier.h"
 
 #include <memory>
 #include <utility>
 
 #include "base/run_loop.h"
+#include "base/test/scoped_task_environment.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "components/invalidation/impl/fake_invalidation_handler.h"
 #include "components/invalidation/impl/fake_invalidation_state_tracker.h"
 #include "components/invalidation/impl/invalidation_state_tracker.h"
 #include "components/invalidation/impl/invalidator_test_template.h"
 #include "components/invalidation/impl/push_client_channel.h"
 #include "jingle/notifier/base/fake_base_task.h"
 #include "jingle/notifier/base/notifier_options.h"
 #include "jingle/notifier/listener/fake_push_client.h"
 #include "net/url_request/url_request_test_util.h"
@@ skipping 46 matching lines @@
   void TriggerOnInvalidatorStateChange(InvalidatorState state) {
     invalidator_->OnInvalidatorStateChange(state);
   }
 
   void TriggerOnIncomingInvalidation(
       const ObjectIdInvalidationMap& invalidation_map) {
     invalidator_->OnInvalidate(invalidation_map);
   }
 
  private:
-  base::MessageLoop message_loop_;
+  base::test::ScopedTaskEnvironment scoped_task_environment_;
   std::unique_ptr<InvalidationNotifier> invalidator_;
 };
 
 INSTANTIATE_TYPED_TEST_CASE_P(
     InvalidationNotifierTest, InvalidatorTest,
     InvalidationNotifierTestDelegate);
 
 }  // namespace
 
 }  // namespace syncer