Use ScopedTaskEnvironment instead of MessageLoopForUI in components tests.

components/sync/device_info/device_info_data_type_controller_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 "components/sync/device_info/device_info_data_type_controller.h"
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/memory/ptr_util.h"
 #include "base/memory/weak_ptr.h"
 #include "base/run_loop.h"
+#include "base/test/scoped_task_environment.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "components/sync/base/model_type.h"
 #include "components/sync/device_info/local_device_info_provider_mock.h"
 #include "components/sync/driver/fake_sync_client.h"
 #include "components/sync/driver/sync_api_component_factory.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace syncer {
 
 namespace {
 
 class DeviceInfoDataTypeControllerTest : public testing::Test {
  public:
   DeviceInfoDataTypeControllerTest()
-      : load_finished_(false),
+      : scoped_task_environment_(
+            base::test::ScopedTaskEnvironment::MainThreadType::UI),
+        load_finished_(false),
         last_type_(UNSPECIFIED),
         weak_ptr_factory_(this) {}
   ~DeviceInfoDataTypeControllerTest() override {}
 
   void SetUp() override {
     local_device_ = base::MakeUnique<LocalDeviceInfoProviderMock>(
         "cache_guid", "Wayne Gretzky's Hacking Box", "Chromium 10k",
         "Chrome 10k", sync_pb::SyncEnums_DeviceType_TYPE_LINUX, "device_id");
 
     controller_ = base::MakeUnique<DeviceInfoDataTypeController>(
@@ skipping 34 matching lines @@
 
     if (last_type_ != DEVICE_INFO) {
       return testing::AssertionFailure()
              << "OnLoadFinished was called with a wrong sync type: "
              << last_type_;
     }
 
     return testing::AssertionSuccess();
   }
 
+ private:
+  base::test::ScopedTaskEnvironment scoped_task_environment_;
+
  protected:
   std::unique_ptr<DeviceInfoDataTypeController> controller_;
   std::unique_ptr<LocalDeviceInfoProviderMock> local_device_;
   bool load_finished_;
 
  private:
-  base::MessageLoopForUI message_loop_;
   ModelType last_type_;
   SyncError last_error_;
   FakeSyncClient sync_client_;
   base::WeakPtrFactory<DeviceInfoDataTypeControllerTest> weak_ptr_factory_;
 };
 
 TEST_F(DeviceInfoDataTypeControllerTest, StartModels) {
   Start();
   EXPECT_EQ(DataTypeController::MODEL_LOADED, controller_->state());
   EXPECT_TRUE(LoadResult());
@@ skipping 19 matching lines @@
   controller_->Stop();
   // Destroy |local_device_| and |controller_| out of order
   // to verify that the controller doesn't crash in the destructor.
   local_device_.reset();
   controller_ = nullptr;
 }
 
 }  // namespace
 
 }  // namespace syncer