Use ScopedTaskEnvironment instead of MessageLoopForUI in ui tests.

ui/app_list/search/history_data_store_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 "ui/app_list/search/history_data_store.h"
+
 #include "base/bind.h"
 #include "base/files/file_util.h"
 #include "base/files/scoped_temp_dir.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
-#include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
+#include "base/test/scoped_task_environment.h"
 #include "base/test/sequenced_worker_pool_owner.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/app_list/search/dictionary_data_store.h"
 #include "ui/app_list/search/history_data.h"
-#include "ui/app_list/search/history_data_store.h"
 
 namespace app_list {
 namespace test {
 
 namespace {
 
 std::string GetDataContent(const HistoryData::Data& data) {
   std::string str = std::string("p:") + data.primary + ";s:";
   bool first = true;
   for (HistoryData::SecondaryDeque::const_iterator it = data.secondary.begin();
        it != data.secondary.end();
        ++it) {
     if (first)
       first = false;
     else
       str += ',';
 
     str += *it;
   }
 
   return str;
 }
 
 }  // namespace
 
 class HistoryDataStoreTest : public testing::Test {
  public:
-  HistoryDataStoreTest() : worker_pool_owner_(2, "AppLanucherTest") {}
+  HistoryDataStoreTest()
+      : scoped_task_environment_(
+            base::test::ScopedTaskEnvironment::MainThreadType::UI),
+        worker_pool_owner_(2, "AppLanucherTest") {}
 
   // testing::Test overrides:
   void SetUp() override {
     ASSERT_TRUE(temp_dir_.CreateUniqueTempDir());
   }
   void TearDown() override {
     // Release |store_| while ui loop is still running.
     store_ = NULL;
   }
 
@@ skipping 27 matching lines @@
  private:
   void OnRead(std::unique_ptr<HistoryData::Associations> associations) {
     associations_.clear();
     if (associations)
       associations->swap(associations_);
 
     if (run_loop_)
       run_loop_->Quit();
   }
 
-  base::MessageLoopForUI message_loop_;
+  base::test::ScopedTaskEnvironment scoped_task_environment_;
   base::ScopedTempDir temp_dir_;
   base::FilePath data_file_;
   std::unique_ptr<base::RunLoop> run_loop_;
   base::SequencedWorkerPoolOwner worker_pool_owner_;
 
   scoped_refptr<HistoryDataStore> store_;
   HistoryData::Associations associations_;
 
   DISALLOW_COPY_AND_ASSIGN(HistoryDataStoreTest);
 };
@@ skipping 67 matching lines @@
   EXPECT_EQ(now, it->second.update_time);
 
   store()->Delete(kQuery);
   Flush();
   Load();
   EXPECT_TRUE(associations().empty());
 }
 
 }  // namespace test
 }  // namespace app_list