Always run PolicyWatcher on UI thread in It2Me host.

remoting/host/policy_hack/policy_watcher_unittest.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 "base/basictypes.h"
 #include "base/bind.h"
 #include "base/json/json_writer.h"
 #include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "base/synchronization/waitable_event.h"
@@ skipping 537 matching lines @@
 }
 
 }  // anonymous namespace
 
 // To dump policy contents, run unit tests with the following flags:
 // out/Debug/remoting_unittests --gtest_filter=*TestRealChromotingPolicy* -v=1
 TEST_F(PolicyWatcherTest, TestRealChromotingPolicy) {
   scoped_refptr<base::SingleThreadTaskRunner> task_runner =
       base::MessageLoop::current()->task_runner();
   scoped_ptr<PolicyWatcher> policy_watcher(
-      PolicyWatcher::Create(nullptr, task_runner));
+      PolicyWatcher::Create(nullptr, task_runner, task_runner));
 
   {
     base::RunLoop run_loop;
     policy_watcher->StartWatching(base::Bind(OnPolicyUpdatedDumpPolicy),
                                   base::Bind(base::DoNothing));
     run_loop.RunUntilIdle();
   }
 
   {
     base::RunLoop run_loop;
     PolicyWatcher* raw_policy_watcher = policy_watcher.release();
     raw_policy_watcher->StopWatching(
         base::Bind(base::IgnoreResult(
                        &base::SequencedTaskRunner::DeleteSoon<PolicyWatcher>),
                    task_runner, FROM_HERE, raw_policy_watcher));
     run_loop.RunUntilIdle();
   }
 
   // Today, the only verification offered by this test is:
   // - Manual verification of policy values dumped by OnPolicyUpdatedDumpPolicy
   // - Automated verification that nothing crashed
 }
 
 #endif
 
 }  // namespace policy_hack
 }  // namespace remoting