Use ScopedTaskEnvironment instead of MessageLoop in components unit tests.

components/sync/engine_impl/sync_manager_impl_unittest.cc

 // 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.
 
 #include "components/sync/engine_impl/sync_manager_impl.h"
 
 #include <cstddef>
 #include <utility>
 
 #include "base/callback.h"
 #include "base/compiler_specific.h"
 #include "base/files/scoped_temp_dir.h"
 #include "base/format_macros.h"
 #include "base/location.h"
 #include "base/metrics/field_trial.h"
 #include "base/run_loop.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/test/scoped_feature_list.h"
+#include "base/test/scoped_task_environment.h"
 #include "base/test/values_test_util.h"
 #include "base/values.h"
 #include "components/sync/base/attachment_id_proto.h"
 #include "components/sync/base/cancelation_signal.h"
 #include "components/sync/base/extensions_activity.h"
 #include "components/sync/base/fake_encryptor.h"
 #include "components/sync/base/hash_util.h"
 #include "components/sync/base/mock_unrecoverable_error_handler.h"
 #include "components/sync/base/model_type_test_util.h"
 #include "components/sync/base/sync_features.h"
@@ skipping 217 matching lines @@
 
   // Save changes to the Directory, destroy it then reload it.
   bool ReloadDir();
 
   UserShare* user_share();
   syncable::Directory* dir();
   SyncEncryptionHandler* encryption_handler();
   PassphraseType GetPassphraseType(BaseTransaction* trans);
 
  private:
-  base::MessageLoop message_loop_;
+  base::test::ScopedTaskEnvironment scoped_task_environment_;
   TestUserShare test_user_share_;
 };
 
 UserShare* SyncApiTest::user_share() {
   return test_user_share_.user_share();
 }
 
 syncable::Directory* SyncApiTest::dir() {
   return test_user_share_.user_share()->directory.get();
 }
@@ skipping 959 matching lines @@
                                                                   true);
     EXPECT_EQ(PassphraseType::CUSTOM_PASSPHRASE, GetPassphraseType());
   }
 
   bool HasUnrecoverableError() {
     return mock_unrecoverable_error_handler_.invocation_count() > 0;
   }
 
  private:
   // Needed by |sync_manager_|.
-  base::MessageLoop message_loop_;
+  base::test::ScopedTaskEnvironment scoped_task_environment_;
   // Needed by |sync_manager_|.
   base::ScopedTempDir temp_dir_;
   // Sync Id's for the roots of the enabled datatypes.
   std::map<ModelType, int64_t> type_roots_;
   scoped_refptr<ExtensionsActivity> extensions_activity_;
 
  protected:
   FakeEncryptor encryptor_;
   SyncManagerImpl sync_manager_;
   CancelationSignal cancelation_signal_;
@@ skipping 2234 matching lines @@
 // SyncManagerInitInvalidStorageTest::GetFactory will return
 // DirectoryBackingStore that ensures that SyncManagerImpl::OpenDirectory fails.
 // SyncManagerImpl initialization is done in SyncManagerTest::SetUp. This test's
 // task is to ensure that SyncManagerImpl reported initialization failure in
 // OnInitializationComplete callback.
 TEST_F(SyncManagerInitInvalidStorageTest, FailToOpenDatabase) {
   EXPECT_FALSE(initialization_succeeded_);
 }
 
 }  // namespace syncer