aura: Remove an unnecessary parameter from DispatcherClient::RunWithDispatcher.

ui/views/widget/desktop_aura/desktop_dispatcher_client.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/views/widget/desktop_aura/desktop_dispatcher_client.h"
 
 #include "base/run_loop.h"
 
 namespace views {
 
 DesktopDispatcherClient::DesktopDispatcherClient() {}
 
 DesktopDispatcherClient::~DesktopDispatcherClient() {}
 
 void DesktopDispatcherClient::RunWithDispatcher(
     base::MessagePumpDispatcher* nested_dispatcher,
-    aura::Window* associated_window,
-    bool nestable_tasks_allowed) {
+    aura::Window* associated_window) {
   // TODO(erg): This class has been copypastad from
   // ash/accelerators/nested_dispatcher_controller.cc. I have left my changes
   // commented out because I don't entirely understand the implications of the
   // change.
   base::MessageLoopForUI* loop = base::MessageLoopForUI::current();
-  bool did_allow_task_nesting = loop->NestableTasksAllowed();
-  loop->SetNestableTasksAllowed(nestable_tasks_allowed);
+  base::MessageLoopForUI::ScopedNestableTaskAllower allow_nested(loop);
 
-  // DefaultAcceleratorDispatcher dispatcher(nested_dispatcher,
-  //                                         associated_window);
   base::RunLoop run_loop(nested_dispatcher);
   run_loop.Run();
-  loop->SetNestableTasksAllowed(did_allow_task_nesting);
 }
 
 }  // namespace views