[Cleanup] Migrate the StatisticsProvider to use the TaskScheduler

chrome/browser/ui/webui/chromeos/login/l10n_util_unittest.cc

 // Copyright 2014 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 "chrome/browser/ui/webui/chromeos/login/l10n_util.h"
 
 #include <stddef.h>
 
 #include <utility>
 
-#include "base/at_exit.h"
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
-#include "base/memory/singleton.h"
-#include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
-#include "base/single_thread_task_runner.h"
+#include "base/test/scoped_task_environment.h"
 #include "base/values.h"
 #include "chrome/browser/chromeos/customization/customization_document.h"
 #include "chrome/browser/chromeos/input_method/input_method_configuration.h"
 #include "chrome/browser/ui/webui/chromeos/login/l10n_util_test_util.h"
 #include "chromeos/system/statistics_provider.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/base/ime/chromeos/component_extension_ime_manager.h"
 
 namespace chromeos {
 
 namespace {
 
-class MachineStatisticsInitializer {
- public:
-  MachineStatisticsInitializer();
-
-  static MachineStatisticsInitializer* GetInstance();
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(MachineStatisticsInitializer);
-};
-
-MachineStatisticsInitializer::MachineStatisticsInitializer() {
-  base::MessageLoop loop;
-  chromeos::system::StatisticsProvider::GetInstance()
-      ->StartLoadingMachineStatistics(loop.task_runner(), false);
-  base::RunLoop().RunUntilIdle();
-}
-
-// static
-MachineStatisticsInitializer* MachineStatisticsInitializer::GetInstance() {
-  return base::Singleton<MachineStatisticsInitializer>::get();
-}
-
 void VerifyOnlyUILanguages(const base::ListValue& list) {
   for (size_t i = 0; i < list.GetSize(); ++i) {
     const base::DictionaryValue* dict;
     ASSERT_TRUE(list.GetDictionary(i, &dict));
     std::string code;
     ASSERT_TRUE(dict->GetString("code", &code));
     EXPECT_NE("is", code)
         << "Icelandic is an example language which has input method "
         << "but can't use it as UI language.";
   }
@@ skipping 10 matching lines @@
       << "Wrong language code at index " << index << ".";
 }
 
 }  // namespace
 
 class L10nUtilTest : public testing::Test {
  public:
   L10nUtilTest();
   ~L10nUtilTest() override;
 
-  // testing::Test:
-  void SetUp() override;
-  void TearDown() override;
-
   void SetInputMethods1();
   void SetInputMethods2();
 
  private:
-  base::ShadowingAtExitManager at_exit_manager_;
+  base::test::ScopedTaskEnvironment scoped_task_environment_;
 
   MockInputMethodManagerWithInputMethods* input_manager_;
 };
 
 L10nUtilTest::L10nUtilTest()
     : input_manager_(new MockInputMethodManagerWithInputMethods) {
+  chromeos::input_method::InitializeForTesting(input_manager_);
+  input_manager_->SetComponentExtensionIMEManager(
+      base::MakeUnique<ComponentExtensionIMEManager>());
+
+  chromeos::system::StatisticsProvider::GetInstance()
+      ->StartLoadingMachineStatistics(false);
+  base::RunLoop().RunUntilIdle();
 }
 
 L10nUtilTest::~L10nUtilTest() {
-}
-
-void L10nUtilTest::SetUp() {
-  chromeos::input_method::InitializeForTesting(input_manager_);
-  input_manager_->SetComponentExtensionIMEManager(
-      base::MakeUnique<ComponentExtensionIMEManager>());
-  MachineStatisticsInitializer::GetInstance();  // Ignore result.
-}
-
-void L10nUtilTest::TearDown() {
   chromeos::input_method::Shutdown();
 }
 
 void L10nUtilTest::SetInputMethods1() {
   input_manager_->AddInputMethod("xkb:us::eng", "us", "en-US");
   input_manager_->AddInputMethod("xkb:fr::fra", "fr", "fr");
   input_manager_->AddInputMethod("xkb:be::fra", "be", "fr");
   input_manager_->AddInputMethod("xkb:is::ice", "is", "is");
 }
 
@@ skipping 100 matching lines @@
   VerifyOnlyUILanguages(*list);
 
   ASSERT_LE(3u, list->GetSize());
 
   VerifyLanguageCode(*list, 0, "it");
   VerifyLanguageCode(*list, 1, "de");
   VerifyLanguageCode(*list, 2, kMostRelevantLanguagesDivider);
 }
 
 }  // namespace chromeos