Share one thread between all AudioOutputControllers instead of creating one per stream.

media/audio/openbsd/audio_manager_openbsd.cc

Index: media/audio/openbsd/audio_manager_openbsd.cc
diff --git a/media/audio/openbsd/audio_manager_openbsd.cc b/media/audio/openbsd/audio_manager_openbsd.cc
index 7d7a249aa1edda30bea9d2767a237a30dc469ced..c2c7b98ee40813ad3107a3f55f61db596ed93268 100644
--- a/media/audio/openbsd/audio_manager_openbsd.cc
+++ b/media/audio/openbsd/audio_manager_openbsd.cc
@@ -4,7 +4,6 @@
 
 #include "media/audio/openbsd/audio_manager_openbsd.h"
 
-#include "base/at_exit.h"
 #include "base/logging.h"
 
 namespace {
@@ -48,6 +47,7 @@ AudioManagerOpenBSD::~AudioManagerOpenBSD() {
 }
 
 void AudioManagerOpenBSD::Init() {
+  AudioManagerBase::Init();
 }
 
 void AudioManagerOpenBSD::MuteAll() {
@@ -71,3 +71,8 @@ AudioManager* AudioManager::GetAudioManager() {
   }
   return g_audio_manager;
 }
+
+// static
+AudioManager* AudioManager::CreateAudioManager() {
+  return new AudioManagerOpenBSD();
+}