Use SingleThreadTaskRunner instead of MessageLoopProxy in remoting/host.

remoting/host/policy_hack/nat_policy_mac.mm

 // 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 "remoting/host/policy_hack/nat_policy.h"
 
 #include <CoreFoundation/CoreFoundation.h>
 
 #include "base/compiler_specific.h"
 #include "base/mac/scoped_cftyperef.h"
 #include "base/memory/scoped_ptr.h"
-#include "base/message_loop_proxy.h"
+#include "base/single_thread_task_runner.h"
 #include "base/sys_string_conversions.h"
 #include "base/values.h"
 
 namespace remoting {
 namespace policy_hack {
 
 // The MacOS version does not watch files because it is accepted
 // practice on the Mac that the user must logout/login for policies to be
 // applied. This will actually pick up policies every
 // |kFallbackReloadDelayMinutes| which is sufficient for right now.
 class NatPolicyMac : public NatPolicy {
  public:
-  explicit NatPolicyMac(base::MessageLoopProxy* message_loop_proxy)
-     : NatPolicy(message_loop_proxy) {
+  explicit NatPolicyMac(scoped_refptr<base::SingleThreadTaskRunner> task_runner)
+     : NatPolicy(task_runner) {
   }
 
   virtual ~NatPolicyMac() {
   }
 
  protected:
   virtual void StartWatchingInternal() OVERRIDE {
     Reload();
   }
 
@@ skipping 19 matching lines @@
 
     // Set policy. Policy must be set (even if it is empty) so that the
     // default policy is picked up the first time reload is called.
     UpdateNatPolicy(&policy);
 
     // Reschedule task.
     ScheduleFallbackReloadTask();
   }
 };
 
-NatPolicy* NatPolicy::Create(base::MessageLoopProxy* message_loop_proxy) {
-  return new NatPolicyMac(message_loop_proxy);
+NatPolicy* NatPolicy::Create(
+        scoped_refptr<base::SingleThreadTaskRunner> task_runner) {
+  return new NatPolicyMac(task_runner);
 }
 
 }  // namespace policy_hack
 }  // namespace remoting