Use ScopedTaskEnvironment instead of MessageLoopForUI in chrome tests.

chrome/browser/ui/app_list/search/history_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 <stddef.h>
 
 #include <memory>
 
 #include "base/bind.h"
 #include "base/files/scoped_temp_dir.h"
 #include "base/macros.h"
-#include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "base/strings/string_number_conversions.h"
+#include "base/test/scoped_task_environment.h"
 #include "base/test/sequenced_worker_pool_owner.h"
 #include "base/threading/platform_thread.h"
 #include "chrome/browser/ui/app_list/search/history_factory.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/app_list/search/dictionary_data_store.h"
 #include "ui/app_list/search/history.h"
 #include "ui/app_list/search/history_data.h"
 #include "ui/app_list/search/history_data_observer.h"
 #include "ui/app_list/search/history_data_store.h"
 
@@ skipping 58 matching lines @@
   HistoryDataStore* store_;  // Not owned.
   std::unique_ptr<base::RunLoop> run_loop_;
 
   DISALLOW_COPY_AND_ASSIGN(StoreFlushWaiter);
 };
 
 }  // namespace
 
 class SearchHistoryTest : public testing::Test {
  public:
-  SearchHistoryTest() {}
+  SearchHistoryTest()
+      : scoped_task_environment_(
+            base::test::ScopedTaskEnvironment::MainThreadType::UI) {}
   ~SearchHistoryTest() override {}
 
   // testing::Test overrides:
   void SetUp() override {
     worker_pool_owner_.reset(
         new base::SequencedWorkerPoolOwner(2, "AppLauncherTest"));
     ASSERT_TRUE(temp_dir_.CreateUniqueTempDir());
     CreateHistory();
   }
   void TearDown() override {
@@ skipping 33 matching lines @@
                ? (*known_results_.get())[result_id]
                : UNKNOWN_RESULT;
   }
 
   History* history() { return history_.get(); }
   const HistoryData::Associations& associations() const {
     return history_->data_->associations();
   }
 
  private:
-  base::MessageLoopForUI message_loop_;
+  base::test::ScopedTaskEnvironment scoped_task_environment_;
   base::ScopedTempDir temp_dir_;
   std::unique_ptr<base::SequencedWorkerPoolOwner> worker_pool_owner_;
 
   std::unique_ptr<History> history_;
   std::unique_ptr<KnownResults> known_results_;
 
   DISALLOW_COPY_AND_ASSIGN(SearchHistoryTest);
 };
 
 TEST_F(SearchHistoryTest, Persistence) {
@@ skipping 138 matching lines @@
 
   // The oldest secondary is gone.
   EXPECT_EQ(UNKNOWN_RESULT, GetResultType("1"));
 
   // Touched oldest survived.
   EXPECT_EQ(PERFECT_SECONDARY, GetResultType("0"));
 }
 
 }  // namespace test
 }  // namespace app_list