Migrate callers of message_loop_proxy() to task_runner()

Migrate callers of {MessageLoop,Thread}::message_loop_proxy() to
{MessageLoop,Thread}::task_runner(). Since the types at the call sites
have already been updated, this is just a bulk rename.

BUG=465354
[email protected]

Review URL: https://codereview.chromium.org/1179163002

Cr-Commit-Position: refs/heads/master@{#334840}
diff --git a/dbus/object_manager_unittest.cc b/dbus/object_manager_unittest.cc
index 76ddb85..34f7ac4 100644
--- a/dbus/object_manager_unittest.cc
+++ b/dbus/object_manager_unittest.cc
@@ -70,7 +70,7 @@
 
     // Start the test service, using the D-Bus thread.
     TestService::Options options;
-    options.dbus_task_runner = dbus_thread_->message_loop_proxy();
+    options.dbus_task_runner = dbus_thread_->task_runner();
     test_service_.reset(new TestService(options));
     ASSERT_TRUE(test_service_->StartService());
     ASSERT_TRUE(test_service_->WaitUntilServiceIsStarted());
@@ -80,7 +80,7 @@
     Bus::Options bus_options;
     bus_options.bus_type = Bus::SESSION;
     bus_options.connection_type = Bus::PRIVATE;
-    bus_options.dbus_task_runner = dbus_thread_->message_loop_proxy();
+    bus_options.dbus_task_runner = dbus_thread_->task_runner();
     bus_ = new Bus(bus_options);
     ASSERT_TRUE(bus_->HasDBusThread());