Use correct thread for audio capturing and encoding.

remoting/host/desktop_environment_factory.cc

Index: remoting/host/desktop_environment_factory.cc
diff --git a/remoting/host/desktop_environment_factory.cc b/remoting/host/desktop_environment_factory.cc
index d9944a441bb3f36687e0a5ccc7f3aa3071a42e67..a0c7f1614a08bd466cb66b3a63e4d7c03c2f9f30 100644
--- a/remoting/host/desktop_environment_factory.cc
+++ b/remoting/host/desktop_environment_factory.cc
@@ -25,12 +25,11 @@ DesktopEnvironmentFactory::~DesktopEnvironmentFactory() {
 
 scoped_ptr<DesktopEnvironment> DesktopEnvironmentFactory::Create(
     ClientSession* client) {
-  scoped_ptr<AudioCapturer> audio_capturer = AudioCapturer::Create();
   scoped_ptr<EventExecutor> event_executor = EventExecutor::Create(
       input_task_runner_, ui_task_runner_);
   scoped_ptr<VideoFrameCapturer> video_capturer(VideoFrameCapturer::Create());
   return scoped_ptr<DesktopEnvironment>(new DesktopEnvironment(
-      audio_capturer.Pass(), event_executor.Pass(), video_capturer.Pass()));
+      event_executor.Pass(), video_capturer.Pass()));
 }
 
 bool DesktopEnvironmentFactory::SupportsAudioCapture() const {