Use ScopedTaskEnvironment instead of MessageLoopForUI in components tests.

components/history/core/browser/history_service_unittest.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.
 
 // History unit tests come in two flavors:
 //
 // 1. The more complicated style is that the unit test creates a full history
 //    service. This spawns a background thread for the history backend, and
 //    all communication is asynchronous. This is useful for testing more
 //    complicated things or end-to-end behavior.
@@ skipping 11 matching lines @@
 #include <stdint.h>
 
 #include "base/files/file_util.h"
 #include "base/files/scoped_temp_dir.h"
 #include "base/location.h"
 #include "base/macros.h"
 #include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "base/single_thread_task_runner.h"
 #include "base/strings/utf_string_conversions.h"
+#include "base/test/scoped_task_environment.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "components/history/core/browser/history_database_params.h"
 #include "components/history/core/browser/history_db_task.h"
 #include "components/history/core/test/database_test_utils.h"
 #include "components/history/core/test/test_history_database.h"
 #include "components/sync/model/attachments/attachment_id.h"
 #include "components/sync/model/attachments/attachment_service_proxy_for_test.h"
 #include "components/sync/model/fake_sync_change_processor.h"
 #include "components/sync/model/sync_change.h"
 #include "components/sync/model/sync_change_processor.h"
 #include "components/sync/model/sync_change_processor_wrapper_for_test.h"
 #include "components/sync/model/sync_error.h"
 #include "components/sync/model/sync_error_factory.h"
 #include "components/sync/model/sync_merge_result.h"
 #include "components/sync/protocol/history_delete_directive_specifics.pb.h"
 #include "components/sync/protocol/sync.pb.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace history {
 
 class HistoryServiceTest : public testing::Test {
  public:
-  HistoryServiceTest() : query_url_success_(false) {}
+  HistoryServiceTest()
+      : scoped_task_environment_(
+            base::test::ScopedTaskEnvironment::MainThreadType::UI),
+        query_url_success_(false) {}
 
   ~HistoryServiceTest() override {}
 
   void OnMostVisitedURLsAvailable(const MostVisitedURLList* url_list) {
     most_visited_urls_ = *url_list;
     base::MessageLoop::current()->QuitWhenIdle();
   }
 
  protected:
   friend class BackendDelegate;
@@ skipping 82 matching lines @@
     saved_redirects_.clear();
     if (!redirects->empty()) {
       saved_redirects_.insert(
           saved_redirects_.end(), redirects->begin(), redirects->end());
     }
     base::MessageLoop::current()->QuitWhenIdle();
   }
 
   base::ScopedTempDir temp_dir_;
 
-  base::MessageLoopForUI message_loop_;
+  base::test::ScopedTaskEnvironment scoped_task_environment_;
 
   MostVisitedURLList most_visited_urls_;
 
   // When non-NULL, this will be deleted on tear down and we will block until
   // the backend thread has completed. This allows tests for the history
   // service to use this feature, but other tests to ignore this.
   std::unique_ptr<history::HistoryService> history_service_;
 
   // names of the database files
   base::FilePath history_dir_;
@@ skipping 726 matching lines @@
   // Expect two sync changes for deleting processed directives.
   const syncer::SyncChangeList& sync_changes = change_processor.changes();
   ASSERT_EQ(2u, sync_changes.size());
   EXPECT_EQ(syncer::SyncChange::ACTION_DELETE, sync_changes[0].change_type());
   EXPECT_EQ(1, syncer::SyncDataRemote(sync_changes[0].sync_data()).GetId());
   EXPECT_EQ(syncer::SyncChange::ACTION_DELETE, sync_changes[1].change_type());
   EXPECT_EQ(2, syncer::SyncDataRemote(sync_changes[1].sync_data()).GetId());
 }
 
 }  // namespace history