Delete left-over references to AsyncInvoker

Bug: webrtc:12339
Change-Id: I16c7e83a043939e76ee7cd0cb9402bc08584eb6c
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/213142
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Commit-Queue: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#33742}

pc/data_channel_controller.h

@@ -233,11 +233,6 @@ class DataChannelController : public RtpDataChannelProviderInterface,
   sigslot::signal1<SctpDataChannel*> SignalSctpDataChannelCreated_
       RTC_GUARDED_BY(signaling_thread());
 
-  // Used from the network thread to invoke data channel transport signals on
-  // the signaling thread.
-  rtc::AsyncInvoker data_channel_transport_invoker_
-      RTC_GUARDED_BY(network_thread());
-
   // Owning PeerConnection.
   PeerConnection* const pc_;
   // The weak pointers must be dereferenced and invalidated on the signalling

pc/rtp_data_channel.h

@@ -25,7 +25,6 @@
 #include "media/base/media_channel.h"
 #include "pc/channel.h"
 #include "pc/data_channel_utils.h"
-#include "rtc_base/async_invoker.h"
 #include "rtc_base/copy_on_write_buffer.h"
 #include "rtc_base/third_party/sigslot/sigslot.h"
 #include "rtc_base/thread.h"

pc/stats_collector.cc

@@ -668,7 +668,7 @@ void StatsCollector::UpdateStats(
       ExtractSessionInfo();
 
   // TODO(tommi): All of these hop over to the worker thread to fetch
-  // information.  We could use an AsyncInvoker to run all of these and post
+  // information.  We could post a task to run all of these and post
   // the information back to the signaling thread where we can create and
   // update stats reports.  That would also clean up the threading story a bit
   // since we'd be creating/updating the stats report objects consistently on

rtc_base/fake_mdns_responder.h

@@ -15,7 +15,6 @@
 #include <memory>
 #include <string>
 
-#include "rtc_base/async_invoker.h"
 #include "rtc_base/ip_address.h"
 #include "rtc_base/location.h"
 #include "rtc_base/mdns_responder_interface.h"