Add RetainedRef uses where needed.

ppapi/proxy/ppapi_proxy_test.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 "ppapi/proxy/ppapi_proxy_test.h"
 
 #include <sstream>
 #include <tuple>
 
 #include "base/bind.h"
@@ skipping 540 matching lines @@
   plugin_thread_.Start();
 
   // Construct the IPC handle name using the process ID so we can safely run
   // multiple |TwoWayTest|s concurrently.
   std::ostringstream handle_name;
   handle_name << "TwoWayTestChannel" << base::GetCurrentProcId();
   IPC::ChannelHandle handle(handle_name.str());
   base::WaitableEvent remote_harness_set_up(true, false);
   plugin_thread_.task_runner()->PostTask(
       FROM_HERE, base::Bind(&SetUpRemoteHarness, remote_harness_, handle,
-                            io_thread_.task_runner(), &shutdown_event_,
-                            &remote_harness_set_up));
+                            base::RetainedRef(io_thread_.task_runner()),
+                            &shutdown_event_, &remote_harness_set_up));
   remote_harness_set_up.Wait();
   local_harness_->SetUpHarnessWithChannel(
       handle, io_thread_.task_runner().get(), &shutdown_event_,
       true);  // is_client
 }
 
 void TwoWayTest::TearDown() {
   base::WaitableEvent remote_harness_torn_down(true, false);
   plugin_thread_.task_runner()->PostTask(
       FROM_HERE, base::Bind(&TearDownRemoteHarness, remote_harness_,
                             &remote_harness_torn_down));
   remote_harness_torn_down.Wait();
 
   local_harness_->TearDownHarness();
 
   io_thread_.Stop();
 }
 
 void TwoWayTest::PostTaskOnRemoteHarness(const base::Closure& task) {
   base::WaitableEvent task_complete(true, false);
   plugin_thread_.task_runner()->PostTask(
       FROM_HERE, base::Bind(&RunTaskOnRemoteHarness, task, &task_complete));
   task_complete.Wait();
 }
 
 
 }  // namespace proxy
 }  // namespace ppapi