Use ScopedTaskEnvironment instead of MessageLoopForUI in chrome tests.

chrome/browser/chromeos/policy/user_cloud_policy_store_chromeos_unittest.cc

 // Copyright (c) 2012 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/chromeos/policy/user_cloud_policy_store_chromeos.h"
 
 #include <stdint.h>
 
 #include <memory>
 #include <string>
 
 #include "base/bind.h"
 #include "base/files/file_util.h"
 #include "base/files/scoped_temp_dir.h"
 #include "base/location.h"
 #include "base/macros.h"
 #include "base/memory/ptr_util.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/threading/sequenced_worker_pool.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "chromeos/dbus/mock_cryptohome_client.h"
 #include "chromeos/dbus/mock_session_manager_client.h"
 #include "components/policy/core/common/cloud/cloud_policy_constants.h"
 #include "components/policy/core/common/cloud/mock_cloud_policy_store.h"
 #include "components/policy/core/common/cloud/policy_builder.h"
 #include "components/policy/core/common/policy_types.h"
 #include "components/policy/policy_constants.h"
 #include "components/policy/proto/cloud_policy.pb.h"
@@ skipping 20 matching lines @@
     "0123456789ABCDEF0123456789ABCDEF012345678@example.com";
 const char kDefaultHomepage[] = "http://chromium.org";
 
 ACTION_P2(SendSanitizedUsername, call_status, sanitized_username) {
   base::ThreadTaskRunnerHandle::Get()->PostTask(
       FROM_HERE, base::Bind(arg1, call_status, sanitized_username));
 }
 
 class UserCloudPolicyStoreChromeOSTest : public testing::Test {
  protected:
-  UserCloudPolicyStoreChromeOSTest() {}
+  UserCloudPolicyStoreChromeOSTest()
+      : scoped_task_environment_(
+            base::test::ScopedTaskEnvironment::MainThreadType::UI) {}
 
   void SetUp() override {
     EXPECT_CALL(cryptohome_client_, GetSanitizedUsername(cryptohome_id_, _))
         .Times(AnyNumber())
         .WillRepeatedly(SendSanitizedUsername(
             chromeos::DBUS_METHOD_CALL_SUCCESS, kSanitizedUsername));
 
     ASSERT_TRUE(tmp_dir_.CreateUniqueTempDir());
     store_.reset(new UserCloudPolicyStoreChromeOS(
         &cryptohome_client_, &session_manager_client_, loop_.task_runner(),
@@ skipping 128 matching lines @@
 
   base::FilePath user_policy_dir() {
     return tmp_dir_.GetPath().AppendASCII("var_run_user_policy");
   }
 
   base::FilePath user_policy_key_file() {
     return user_policy_dir().AppendASCII(kSanitizedUsername)
                             .AppendASCII("policy.pub");
   }
 
-  base::MessageLoopForUI loop_;
+  base::test::ScopedTaskEnvironment scoped_task_environment_;
   chromeos::MockCryptohomeClient cryptohome_client_;
   chromeos::MockSessionManagerClient session_manager_client_;
   UserPolicyBuilder policy_;
   MockCloudPolicyStoreObserver observer_;
   std::unique_ptr<UserCloudPolicyStoreChromeOS> store_;
   const AccountId account_id_ =
       AccountId::FromUserEmail(PolicyBuilder::kFakeUsername);
   const cryptohome::Identification cryptohome_id_ =
       cryptohome::Identification(account_id_);
 
@@ skipping 365 matching lines @@
 
   EXPECT_FALSE(store_->policy());
   EXPECT_TRUE(store_->policy_map().empty());
   EXPECT_EQ(CloudPolicyStore::STATUS_VALIDATION_ERROR, store_->status());
   EXPECT_EQ(std::string(), store_->policy_signature_public_key());
 }
 
 }  // namespace
 
 }  // namespace policy