Don't inject worker queue into send streams.

This prepares for making AudioSendStream use its own task queue. In the
future more of the functionality that depends on running on the task
queue is planned to be moved directly into RtpTransportControllerSend.

They should instead get it from the transport controller. This affects
the media transport tests which previously assumed that the transport
controller could be missing. However, this is not something that is used
in production, so this is an improvement of the tests as they will
behave more like production code.

Bug: webrtc:9883
Change-Id: Ie32f4c2f6433ec37ac16a08d531ceb690ea9c0b5
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/126000
Reviewed-by: Oskar Sundbom <ossu@webrtc.org>
Reviewed-by: Niels Moller <nisse@webrtc.org>
Reviewed-by: Erik Språng <sprang@webrtc.org>
Commit-Queue: Sebastian Jansson <srte@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#27010}
diff --git a/audio/audio_send_stream_unittest.cc b/audio/audio_send_stream_unittest.cc
index df5ee30..80d5ad4 100644
--- a/audio/audio_send_stream_unittest.cc
+++ b/audio/audio_send_stream_unittest.cc
@@ -13,6 +13,7 @@
 #include <vector>
 
 #include "absl/memory/memory.h"
+#include "api/task_queue/global_task_queue_factory.h"
 #include "api/test/mock_frame_encryptor.h"
 #include "audio/audio_send_stream.h"
 #include "audio/audio_state.h"
@@ -161,11 +162,13 @@
   }
 
   std::unique_ptr<internal::AudioSendStream> CreateAudioSendStream() {
+    EXPECT_CALL(rtp_transport_, GetWorkerQueue())
+        .WillRepeatedly(Return(&worker_queue_));
     return std::unique_ptr<internal::AudioSendStream>(
         new internal::AudioSendStream(
             Clock::GetRealTimeClock(), stream_config_, audio_state_,
-            &worker_queue_, &rtp_transport_, &bitrate_allocator_, &event_log_,
-            &rtcp_rtt_stats_, absl::nullopt,
+            &rtp_transport_, &bitrate_allocator_, &event_log_, &rtcp_rtt_stats_,
+            absl::nullopt,
             std::unique_ptr<voe::ChannelSendInterface>(channel_send_)));
   }