Revert of Add task queue to Call.

webrtc/audio/audio_send_stream.h

Index: webrtc/audio/audio_send_stream.h
diff --git a/webrtc/audio/audio_send_stream.h b/webrtc/audio/audio_send_stream.h
index 3629463162261d1ab48a2d2f8e21bc5b76d17bfd..a993d5f2f9c03f4add6ea239a9123f3b7bae1a6c 100644
--- a/webrtc/audio/audio_send_stream.h
+++ b/webrtc/audio/audio_send_stream.h
@@ -33,7 +33,6 @@
  public:
   AudioSendStream(const webrtc::AudioSendStream::Config& config,
                   const rtc::scoped_refptr<webrtc::AudioState>& audio_state,
-                  rtc::TaskQueue* worker_queue,
                   CongestionController* congestion_controller,
                   BitrateAllocator* bitrate_allocator);
   ~AudioSendStream() override;
@@ -60,7 +59,6 @@
   VoiceEngine* voice_engine() const;
 
   rtc::ThreadChecker thread_checker_;
-  rtc::TaskQueue* worker_queue_;
   const webrtc::AudioSendStream::Config config_;
   rtc::scoped_refptr<webrtc::AudioState> audio_state_;
   std::unique_ptr<voe::ChannelProxy> channel_proxy_;