Fix breakages while performance_browser_tests was not running on Mac.

media/cast/test/utility/standalone_cast_environment.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 "media/cast/test/utility/standalone_cast_environment.h"
 
 #include "base/memory/ptr_util.h"
 #include "base/message_loop/message_loop.h"
+#include "base/threading/thread_restrictions.h"
 #include "base/time/default_tick_clock.h"
 
 namespace media {
 namespace cast {
 
 StandaloneCastEnvironment::StandaloneCastEnvironment()
     : CastEnvironment(
           base::WrapUnique<base::TickClock>(new base::DefaultTickClock()),
           NULL,
           NULL,
@@ skipping 14 matching lines @@
 
 StandaloneCastEnvironment::~StandaloneCastEnvironment() {
   CHECK(CalledOnValidThread());
   CHECK(!main_thread_.IsRunning());
   CHECK(!audio_thread_.IsRunning());
   CHECK(!video_thread_.IsRunning());
 }
 
 void StandaloneCastEnvironment::Shutdown() {
   CHECK(CalledOnValidThread());
+
+  base::ThreadRestrictions::ScopedAllowIO
+      because_i_brought_you_into_this_world_and_i_am_gonna_take_you_out;
   main_thread_.Stop();
   audio_thread_.Stop();
   video_thread_.Stop();
 }
 
 }  // namespace cast
 }  // namespace media