Dart: Remove shutdown workarounds.

services/dart/content_handler_main.cc

 // Copyright 2014 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 "base/bind.h"
 #include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "base/strings/string_util.h"
 #include "base/synchronization/waitable_event.h"
 #include "base/threading/platform_thread.h"
@@ skipping 229 matching lines @@
                     url,
                     strict_,
                     run_on_message_loop));
   }
 }
 
 }  // namespace dart
 
 MojoResult MojoMain(MojoHandle application_request) {
   mojo::ApplicationRunnerChromium runner(new dart::DartContentHandlerApp);
-  MojoResult r = runner.Run(application_request);
-  // TODO(johnmccutchan): Remove this once the Dart VM shuts down threads.
-  base::PlatformThread::Sleep(base::TimeDelta::FromMilliseconds(100));
-  return r;
+  return runner.Run(application_request);
 }