Use ScopedTaskEnvironment instead of MessageLoopForUI in components tests.

components/policy/core/common/cloud/user_cloud_policy_store_unittest.cc

Index: components/policy/core/common/cloud/user_cloud_policy_store_unittest.cc
diff --git a/components/policy/core/common/cloud/user_cloud_policy_store_unittest.cc b/components/policy/core/common/cloud/user_cloud_policy_store_unittest.cc
index c1f7272479e0547bd874de262058386e2c1a35cb..b07c5d5b141aff623e7bcec86af6881fefe71b3e 100644
--- a/components/policy/core/common/cloud/user_cloud_policy_store_unittest.cc
+++ b/components/policy/core/common/cloud/user_cloud_policy_store_unittest.cc
@@ -8,6 +8,8 @@
 #include "base/files/scoped_temp_dir.h"
 #include "base/macros.h"
 #include "base/run_loop.h"
+#include "base/test/scoped_task_environment.h"
+#include "base/threading/thread_task_runner_handle.h"
 #include "components/policy/core/common/cloud/cloud_policy_constants.h"
 #include "components/policy/core/common/cloud/mock_cloud_external_data_manager.h"
 #include "components/policy/core/common/cloud/mock_cloud_policy_store.h"
@@ -52,12 +54,14 @@ bool WriteStringToFile(const base::FilePath path, const std::string& data) {
 
 class UserCloudPolicyStoreTest : public testing::Test {
  public:
-  UserCloudPolicyStoreTest() {}
+  UserCloudPolicyStoreTest()
+      : scoped_task_environment_(
+            base::test::ScopedTaskEnvironment::MainThreadType::UI) {}
 
   void SetUp() override {
     ASSERT_TRUE(tmp_dir_.CreateUniqueTempDir());
     store_.reset(new UserCloudPolicyStore(policy_file(), key_file(),
-                                          loop_.task_runner()));
+                                          base::ThreadTaskRunnerHandle::Get()));
     external_data_manager_.reset(new MockCloudExternalDataManager);
     external_data_manager_->SetPolicyStore(store_.get());
     store_->SetSigninUsername(PolicyBuilder::kFakeUsername);
@@ -130,10 +134,7 @@ class UserCloudPolicyStoreTest : public testing::Test {
   std::unique_ptr<UserCloudPolicyStore> store_;
   std::unique_ptr<MockCloudExternalDataManager> external_data_manager_;
 
-  // CloudPolicyValidator() requires a FILE thread so declare one here. Both
-  // |ui_thread_| and |file_thread_| share the same MessageLoop |loop_| so
-  // callers can use RunLoop to manage both virtual threads.
-  base::MessageLoopForUI loop_;
+  base::test::ScopedTaskEnvironment scoped_task_environment_;
 
   base::ScopedTempDir tmp_dir_;
 
@@ -353,8 +354,8 @@ TEST_F(UserCloudPolicyStoreTest, StoreThenLoad) {
   EXPECT_FALSE(store_->policy_signature_public_key().empty());
 
   // Now, make sure the policy can be read back in from a second store.
-  std::unique_ptr<UserCloudPolicyStore> store2(
-      new UserCloudPolicyStore(policy_file(), key_file(), loop_.task_runner()));
+  std::unique_ptr<UserCloudPolicyStore> store2(new UserCloudPolicyStore(
+      policy_file(), key_file(), base::ThreadTaskRunnerHandle::Get()));
   store2->SetSigninUsername(PolicyBuilder::kFakeUsername);
   store2->AddObserver(&observer_);
   EXPECT_CALL(observer_, OnStoreLoaded(store2.get()));
@@ -378,8 +379,8 @@ TEST_F(UserCloudPolicyStoreTest, StoreThenLoadImmediately) {
   StorePolicyAndEnsureLoaded(policy_.policy());
 
   // Now, make sure the policy can be read back in from a second store.
-  std::unique_ptr<UserCloudPolicyStore> store2(
-      new UserCloudPolicyStore(policy_file(), key_file(), loop_.task_runner()));
+  std::unique_ptr<UserCloudPolicyStore> store2(new UserCloudPolicyStore(
+      policy_file(), key_file(), base::ThreadTaskRunnerHandle::Get()));
   store2->SetSigninUsername(PolicyBuilder::kFakeUsername);
   store2->AddObserver(&observer_);
   EXPECT_CALL(observer_, OnStoreLoaded(store2.get()));
@@ -422,8 +423,8 @@ TEST_F(UserCloudPolicyStoreTest, LoadValidationError) {
 
   // Sign out, and sign back in as a different user, and try to load the profile
   // data (should fail due to mismatched username).
-  std::unique_ptr<UserCloudPolicyStore> store2(
-      new UserCloudPolicyStore(policy_file(), key_file(), loop_.task_runner()));
+  std::unique_ptr<UserCloudPolicyStore> store2(new UserCloudPolicyStore(
+      policy_file(), key_file(), base::ThreadTaskRunnerHandle::Get()));
   store2->SetSigninUsername("foobar@foobar.com");
   store2->AddObserver(&observer_);
   ExpectError(store2.get(), CloudPolicyStore::STATUS_VALIDATION_ERROR);
@@ -435,8 +436,8 @@ TEST_F(UserCloudPolicyStoreTest, LoadValidationError) {
 
   // Sign out - we should be able to load the policy (don't check usernames
   // when signed out).
-  std::unique_ptr<UserCloudPolicyStore> store3(
-      new UserCloudPolicyStore(policy_file(), key_file(), loop_.task_runner()));
+  std::unique_ptr<UserCloudPolicyStore> store3(new UserCloudPolicyStore(
+      policy_file(), key_file(), base::ThreadTaskRunnerHandle::Get()));
   store3->AddObserver(&observer_);
   EXPECT_CALL(observer_, OnStoreLoaded(store3.get()));
   store3->Load();
@@ -446,8 +447,8 @@ TEST_F(UserCloudPolicyStoreTest, LoadValidationError) {
   store3->RemoveObserver(&observer_);
 
   // Now start a signin as a different user - this should fail validation.
-  std::unique_ptr<UserCloudPolicyStore> store4(
-      new UserCloudPolicyStore(policy_file(), key_file(), loop_.task_runner()));
+  std::unique_ptr<UserCloudPolicyStore> store4(new UserCloudPolicyStore(
+      policy_file(), key_file(), base::ThreadTaskRunnerHandle::Get()));
   store4->SetSigninUsername("foobar@foobar.com");
   store4->AddObserver(&observer_);
   ExpectError(store4.get(), CloudPolicyStore::STATUS_VALIDATION_ERROR);
@@ -474,8 +475,8 @@ TEST_F(UserCloudPolicyStoreTest, KeyRotation) {
 
   // Now load this in a new store - this should trigger key rotation. The keys
   // will still verify using the existing verification key.
-  std::unique_ptr<UserCloudPolicyStore> store2(
-      new UserCloudPolicyStore(policy_file(), key_file(), loop_.task_runner()));
+  std::unique_ptr<UserCloudPolicyStore> store2(new UserCloudPolicyStore(
+      policy_file(), key_file(), base::ThreadTaskRunnerHandle::Get()));
   store2->SetSigninUsername(PolicyBuilder::kFakeUsername);
   store2->AddObserver(&observer_);
   EXPECT_CALL(observer_, OnStoreLoaded(store2.get()));
@@ -500,8 +501,8 @@ TEST_F(UserCloudPolicyStoreTest, InvalidCachedVerificationSignature) {
 
   // Now load this in a new store - this should cause a validation error because
   // the key won't verify.
-  std::unique_ptr<UserCloudPolicyStore> store2(
-      new UserCloudPolicyStore(policy_file(), key_file(), loop_.task_runner()));
+  std::unique_ptr<UserCloudPolicyStore> store2(new UserCloudPolicyStore(
+      policy_file(), key_file(), base::ThreadTaskRunnerHandle::Get()));
   store2->SetSigninUsername(PolicyBuilder::kFakeUsername);
   store2->AddObserver(&observer_);
   ExpectError(store2.get(), CloudPolicyStore::STATUS_VALIDATION_ERROR);