Add AudioSendStream::SetMuted() method and use it in WVoMC::MuteStream().

webrtc/audio/audio_send_stream.cc

Index: webrtc/audio/audio_send_stream.cc
diff --git a/webrtc/audio/audio_send_stream.cc b/webrtc/audio/audio_send_stream.cc
index 9aa2fc004c2295dc2c2c6bdb97996f6d0d6848c0..d08bfeaa1ef70c43de1de0fd57f1e252966542ec 100644
--- a/webrtc/audio/audio_send_stream.cc
+++ b/webrtc/audio/audio_send_stream.cc
@@ -127,6 +127,11 @@ bool AudioSendStream::SendTelephoneEvent(int payload_type, int event,
          channel_proxy_->SendTelephoneEventOutband(event, duration_ms);
 }
 
+void AudioSendStream::SetMuted(bool muted) {
+  RTC_DCHECK(thread_checker_.CalledOnValidThread());
+  channel_proxy_->SetInputMute(muted);
+}
+
 webrtc::AudioSendStream::Stats AudioSendStream::GetStats() const {
   RTC_DCHECK(thread_checker_.CalledOnValidThread());
   webrtc::AudioSendStream::Stats stats;