[scheduling] Use ScopedTaskEnvironment instead of MessageLoop in cloud_print

MessageLoop will go away, eventually.

BUG=891670

Change-Id: Id593e33312007602c236f9f0452a0b6cb0ed4bd4
Reviewed-on: https://chromium-review.googlesource.com/c/1451921
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Carlos Caballero <carlscab@google.com>
Cr-Commit-Position: refs/heads/master@{#628809}
diff --git a/chrome/service/cloud_print/connector_settings_unittest.cc b/chrome/service/cloud_print/connector_settings_unittest.cc
index 3b870e6..da4e309 100644
--- a/chrome/service/cloud_print/connector_settings_unittest.cc
+++ b/chrome/service/cloud_print/connector_settings_unittest.cc
@@ -10,9 +10,9 @@
 
 #include "base/files/file_util.h"
 #include "base/files/scoped_temp_dir.h"
-#include "base/message_loop/message_loop.h"
 #include "base/single_thread_task_runner.h"
 #include "base/stl_util.h"
+#include "base/test/scoped_task_environment.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/values.h"
 #include "chrome/common/cloud_print/cloud_print_constants.h"
@@ -72,7 +72,7 @@
   }
 
   base::ScopedTempDir temp_dir_;
-  base::MessageLoop message_loop_;
+  base::test::ScopedTaskEnvironment scoped_task_environment_;
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
 };