Remove unnecessary uses of aura::Env::GetDispatcher

ui/aura/test/aura_test_helper.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/aura/test/aura_test_helper.h"
 
 #include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/client/default_activation_client.h"
@@ skipping 97 matching lines @@
   ui::ShutdownInputMethodForTesting();
 
   Env::DeleteInstance();
 
   ui::TerminateContextFactoryForTests();
 }
 
 void AuraTestHelper::RunAllPendingInMessageLoop() {
   // TODO(jbates) crbug.com/134753 Find quitters of this RunLoop and have them
   //              use run_loop.QuitClosure().
-  base::RunLoop run_loop(Env::GetInstance()->GetDispatcher());
+  base::RunLoop run_loop;
   run_loop.RunUntilIdle();
 }
 
 }  // namespace test
 }  // namespace aura