Use ScopedTaskEnvironment instead of MessageLoop in components unit tests.

components/autofill/core/browser/autofill_metrics_unittest.cc

 // Copyright 2013 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/autofill/core/browser/autofill_metrics.h"
 
 #include <stddef.h>
 
 #include <memory>
 #include <vector>
 
 #include "base/feature_list.h"
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
 #include "base/metrics/metrics_hashes.h"
 #include "base/run_loop.h"
 #include "base/strings/string16.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/test/histogram_tester.h"
 #include "base/test/scoped_feature_list.h"
+#include "base/test/scoped_task_environment.h"
 #include "base/test/user_action_tester.h"
 #include "base/time/time.h"
 #include "components/autofill/core/browser/autofill_experiments.h"
 #include "components/autofill/core/browser/autofill_external_delegate.h"
 #include "components/autofill/core/browser/autofill_manager.h"
 #include "components/autofill/core/browser/autofill_test_utils.h"
 #include "components/autofill/core/browser/payments/payments_client.h"
 #include "components/autofill/core/browser/personal_data_manager.h"
 #include "components/autofill/core/browser/popup_item_ids.h"
 #include "components/autofill/core/browser/test_autofill_client.h"
@@ skipping 295 matching lines @@
  public:
   ~AutofillMetricsTest() override;
 
   void SetUp() override;
   void TearDown() override;
 
  protected:
   void EnableWalletSync();
   void EnableUkmLogging();
 
-  base::MessageLoop message_loop_;
+  base::test::ScopedTaskEnvironment scoped_task_environment_;
   TestAutofillClient autofill_client_;
   std::unique_ptr<AccountTrackerService> account_tracker_;
   std::unique_ptr<FakeSigninManagerBase> signin_manager_;
   std::unique_ptr<TestSigninClient> signin_client_;
   std::unique_ptr<TestAutofillDriver> autofill_driver_;
   std::unique_ptr<TestAutofillManager> autofill_manager_;
   std::unique_ptr<TestPersonalDataManager> personal_data_;
   std::unique_ptr<AutofillExternalDelegate> external_delegate_;
   base::test::ScopedFeatureList scoped_feature_list_;
 };
@@ skipping 4348 matching lines @@
   ukm::UkmServiceTestingHarness ukm_service_test_harness;
   GURL url("https://www.google.com");
   std::map<std::string, int> metrics = {{"metric", 1}};
 
   EXPECT_FALSE(AutofillMetrics::LogUkm(
       ukm_service_test_harness.test_ukm_service(), url, "test_ukm", metrics));
   EXPECT_EQ(0U, ukm_service_test_harness.test_ukm_service()->sources_count());
 }
 
 }  // namespace autofill