Remove MessageLoop references in services/service_manager/tests/connect

MessageLoop is going away soon.

This CL was uploaded by git cl split.

R=jam@chromium.org

Bug: 891670
Change-Id: I224d419e31a6fb41156fed62bf856674fc69e6e9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1878372Reviewed-by: John Abd-El-Malek <jam@chromium.org>
Commit-Queue: Carlos Caballero <carlscab@google.com>
Auto-Submit: Carlos Caballero <carlscab@google.com>
Cr-Commit-Position: refs/heads/master@{#709874}

services/service_manager/tests/connect/connect_test_exe.cc

@@ -6,7 +6,7 @@
 
 #include "base/bind.h"
 #include "base/macros.h"
-#include "base/message_loop/message_loop.h"
+#include "base/task/single_thread_task_executor.h"
 #include "mojo/public/cpp/bindings/binding_set.h"
 #include "services/service_manager/public/cpp/binder_registry.h"
 #include "services/service_manager/public/cpp/service.h"
@@ -62,6 +62,6 @@ class Target : public service_manager::Service,
 }  // namespace
 
 void ServiceMain(service_manager::mojom::ServiceRequest request) {
-  base::MessageLoop message_loop;
+  base::SingleThreadTaskExecutor executor;
   Target(std::move(request)).RunUntilTermination();
 }