Switching WebRTC browser test from AudioManager::HasAudioOutputDevices() to AudioSystem interface.

media/audio/audio_system_impl.cc

Index: media/audio/audio_system_impl.cc
diff --git a/media/audio/audio_system_impl.cc b/media/audio/audio_system_impl.cc
index 00ea330761b28861dc27bd55cdc39f9ffc1c8337..7504744d42173a3c2529a59f3e169970821f94de 100644
--- a/media/audio/audio_system_impl.cc
+++ b/media/audio/audio_system_impl.cc
@@ -121,6 +121,20 @@ void AudioSystemImpl::HasInputDevices(OnBoolCallback on_has_devices_cb) const {
       std::move(on_has_devices_cb));
 }
 
+void AudioSystemImpl::HasOutputDevices(OnBoolCallback on_has_devices_cb) const {
+  if (GetTaskRunner()->BelongsToCurrentThread()) {
+    GetTaskRunner()->PostTask(
+        FROM_HERE,
+        base::Bind(on_has_devices_cb, audio_manager_->HasAudioOutputDevices()));
+    return;
+  }
+  base::PostTaskAndReplyWithResult(
+      GetTaskRunner(), FROM_HERE,
+      base::Bind(&AudioManager::HasAudioOutputDevices,
+                 base::Unretained(audio_manager_)),
+      std::move(on_has_devices_cb));
+}
+
 void AudioSystemImpl::GetDeviceDescriptions(
     OnDeviceDescriptionsCallback on_descriptions_cp,
     bool for_input) {