Backport some tests in /dbus to SingleThreadTaskEnvironment

These tests were previously migrated from single-threaded MessageLoop to
a multi-threaded TaskEnvironment (then named ScopedTaskEnvironment) as
part of crbug.com/891670.

//base OWNERS decided in retrospect that it was better to keep a
single-threaded option for TaskEnvironment and introduced
SingleThreadTaskEnvironment. This CL retrofits that decision for
/dbus.

This CL is a no-op if it passes CQ.

This CL was uploaded by git cl split.

R=hashimoto@chromium.org

Bug: 891670
Change-Id: I05ed8a9c81b692d2deda1ebb32abfce3011f15cf
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1786754
Auto-Submit: Gabriel Charette <gab@chromium.org>
Commit-Queue: Ryo Hashimoto <hashimoto@chromium.org>
Reviewed-by: Ryo Hashimoto <hashimoto@chromium.org>
Cr-Commit-Position: refs/heads/master@{#694664}

dbus/bus_unittest.cc

@@ -130,7 +130,7 @@ TEST(BusTest, GetObjectProxyIgnoreUnknownService) {
 }
 
 TEST(BusTest, RemoveObjectProxy) {
-  base::test::TaskEnvironment task_environment;
+  base::test::SingleThreadTaskEnvironment task_environment;
 
   // Start the D-Bus thread.
   base::Thread::Options thread_options;
@@ -318,8 +318,8 @@ TEST(BusTest, DoubleAddAndRemoveMatch) {
 }
 
 TEST(BusTest, ListenForServiceOwnerChange) {
-  base::test::TaskEnvironment task_environment(
-      base::test::TaskEnvironment::MainThreadType::IO);
+  base::test::SingleThreadTaskEnvironment task_environment(
+      base::test::SingleThreadTaskEnvironment::MainThreadType::IO);
 
   RunLoopWithExpectedCount run_loop_state;
 

dbus/end_to_end_async_unittest.cc

@@ -256,7 +256,7 @@ class EndToEndAsyncTest : public testing::Test {
     run_loop_->Run();
   }
 
-  base::test::TaskEnvironment task_environment_;
+  base::test::SingleThreadTaskEnvironment task_environment_;
   std::unique_ptr<base::RunLoop> run_loop_;
   std::vector<std::string> response_strings_;
   std::vector<std::string> error_names_;

dbus/mock_unittest.cc

@@ -83,7 +83,7 @@ class MockTest : public testing::Test {
 
  protected:
   std::string response_string_;
-  base::test::TaskEnvironment task_environment_;
+  base::test::SingleThreadTaskEnvironment task_environment_;
   std::unique_ptr<base::RunLoop> run_loop_;
   scoped_refptr<MockBus> mock_bus_;
   scoped_refptr<MockObjectProxy> mock_proxy_;

dbus/object_manager_unittest.cc

@@ -206,7 +206,7 @@ class ObjectManagerTest
     WaitForMethodCallback();
   }
 
-  base::test::TaskEnvironment task_environment_;
+  base::test::SingleThreadTaskEnvironment task_environment_;
   std::unique_ptr<base::RunLoop> run_loop_;
   std::unique_ptr<base::Thread> dbus_thread_;
   scoped_refptr<Bus> bus_;

dbus/property_unittest.cc

@@ -159,7 +159,7 @@ class PropertyTest : public testing::Test {
     }
   }
 
-  base::test::TaskEnvironment task_environment_;
+  base::test::SingleThreadTaskEnvironment task_environment_;
   std::unique_ptr<base::RunLoop> run_loop_;
   std::unique_ptr<base::Thread> dbus_thread_;
   scoped_refptr<Bus> bus_;

dbus/signal_sender_verification_unittest.cc

@@ -167,7 +167,7 @@ class SignalSenderVerificationTest : public testing::Test {
     base::ThreadRestrictions::SetIOAllowed(false);
   }
 
-  base::test::TaskEnvironment task_environment_;
+  base::test::SingleThreadTaskEnvironment task_environment_;
   std::unique_ptr<base::RunLoop> run_loop_;
   std::unique_ptr<base::Thread> dbus_thread_;
   scoped_refptr<Bus> bus_;