Bug 1766646 - Vendor libwebrtc from e091fd21d6

Upstream commit: https://webrtc.googlesource.com/src/+/e091fd21d6c70699c61f32f11b6687143fed3410
    Remove lock from RtpStreamReceiverController.

    The demuxer variable is now being used from the same thread consistently
    so it's safe to replace the lock with a sequence checker.

    Down the line, we may move construction+use of the
    RtpStreamReceiverController class in Call, over to the network thread.
    This should be possible without further modifications to
    RtpStreamReceiverController.

    Bug: webrtc:11993, webrtc:11567
    Change-Id: Iee8c31ddf9b26b39393f40b5b1d25343b0233ae3
    Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/202245
    Reviewed-by: Niels Moller <nisse@webrtc.org>
    Commit-Queue: Tommi <tommi@webrtc.org>
    Cr-Commit-Position: refs/heads/master@{#33016}

third_party/libwebrtc/README.moz-ff-commit

@@ -2586,3 +2586,6 @@ be93b788c6
 # MOZ_LIBWEBRTC_SRC=/home/mfroman/git-checkouts/trial-webrtc-builds/moz-libwebrtc-checkout/src MOZ_LIBWEBRTC_COMMIT=mjfdev bash dom/media/webrtc/third_party_build/fast-forward-libwebrtc.sh
 # base of lastest vendoring
 8467cf27ac
+# MOZ_LIBWEBRTC_SRC=/home/mfroman/git-checkouts/trial-webrtc-builds/moz-libwebrtc-checkout/src MOZ_LIBWEBRTC_COMMIT=mjfdev bash dom/media/webrtc/third_party_build/fast-forward-libwebrtc.sh
+# base of lastest vendoring
+e091fd21d6

third_party/libwebrtc/README.mozilla

@@ -1726,3 +1726,5 @@ libwebrtc updated from /home/mfroman/git-checkouts/trial-webrtc-builds/moz-libwe
 libwebrtc updated from /home/mfroman/git-checkouts/trial-webrtc-builds/moz-libwebrtc-checkout/src commit mjfdev on 2022-04-28T20:33:03.076436.
 # python3 vendor-libwebrtc.py --from-local /home/mfroman/git-checkouts/trial-webrtc-builds/moz-libwebrtc-checkout/src --commit mjfdev libwebrtc
 libwebrtc updated from /home/mfroman/git-checkouts/trial-webrtc-builds/moz-libwebrtc-checkout/src commit mjfdev on 2022-04-28T20:33:51.879551.
+# python3 vendor-libwebrtc.py --from-local /home/mfroman/git-checkouts/trial-webrtc-builds/moz-libwebrtc-checkout/src --commit mjfdev libwebrtc
+libwebrtc updated from /home/mfroman/git-checkouts/trial-webrtc-builds/moz-libwebrtc-checkout/src commit mjfdev on 2022-04-28T21:51:57.173011.

third_party/libwebrtc/call/rtp_demuxer.cc

@@ -91,7 +91,7 @@ std::string RtpDemuxer::DescribePacket(const RtpPacketReceived& packet) {
   return sb.Release();
 }
 
-RtpDemuxer::RtpDemuxer() = default;
+RtpDemuxer::RtpDemuxer(bool use_mid /* = true*/) : use_mid_(use_mid) {}
 
 RtpDemuxer::~RtpDemuxer() {
   RTC_DCHECK(sink_by_mid_.empty());

third_party/libwebrtc/call/rtp_demuxer.h

@@ -94,7 +94,7 @@ class RtpDemuxer {
   // relevant for demuxing.
   static std::string DescribePacket(const RtpPacketReceived& packet);
 
-  RtpDemuxer();
+  explicit RtpDemuxer(bool use_mid = true);
   ~RtpDemuxer();
 
   RtpDemuxer(const RtpDemuxer&) = delete;
@@ -132,10 +132,6 @@ class RtpDemuxer {
   // if the packet was forwarded and false if the packet was dropped.
   bool OnRtpPacket(const RtpPacketReceived& packet);
 
-  // Configure whether to look at the MID header extension when demuxing
-  // incoming RTP packets. By default this is enabled.
-  void set_use_mid(bool use_mid) { use_mid_ = use_mid; }
-
  private:
   // Returns true if adding a sink with the given criteria would cause conflicts
   // with the existing criteria and should be rejected.
@@ -191,7 +187,7 @@ class RtpDemuxer {
   // Adds a binding from the SSRC to the given sink.
   void AddSsrcSinkBinding(uint32_t ssrc, RtpPacketSinkInterface* sink);
 
-  bool use_mid_ = true;
+  const bool use_mid_;
 };
 
 }  // namespace webrtc

third_party/libwebrtc/call/rtp_stream_receiver_controller.cc

@@ -37,11 +37,7 @@ RtpStreamReceiverController::Receiver::~Receiver() {
   controller_->RemoveSink(sink_);
 }
 
-RtpStreamReceiverController::RtpStreamReceiverController() {
-  // At this level the demuxer is only configured to demux by SSRC, so don't
-  // worry about MIDs (MIDs are handled by upper layers).
-  demuxer_.set_use_mid(false);
-}
+RtpStreamReceiverController::RtpStreamReceiverController() {}
 
 RtpStreamReceiverController::~RtpStreamReceiverController() = default;
 
@@ -52,19 +48,19 @@ RtpStreamReceiverController::CreateReceiver(uint32_t ssrc,
 }
 
 bool RtpStreamReceiverController::OnRtpPacket(const RtpPacketReceived& packet) {
-  rtc::CritScope cs(&lock_);
+  RTC_DCHECK_RUN_ON(&demuxer_sequence_);
   return demuxer_.OnRtpPacket(packet);
 }
 
 bool RtpStreamReceiverController::AddSink(uint32_t ssrc,
                                           RtpPacketSinkInterface* sink) {
-  rtc::CritScope cs(&lock_);
+  RTC_DCHECK_RUN_ON(&demuxer_sequence_);
   return demuxer_.AddSink(ssrc, sink);
 }
 
 size_t RtpStreamReceiverController::RemoveSink(
     const RtpPacketSinkInterface* sink) {
-  rtc::CritScope cs(&lock_);
+  RTC_DCHECK_RUN_ON(&demuxer_sequence_);
   return demuxer_.RemoveSink(sink);
 }
 

third_party/libwebrtc/call/rtp_stream_receiver_controller.h

@@ -14,7 +14,7 @@
 
 #include "call/rtp_demuxer.h"
 #include "call/rtp_stream_receiver_controller_interface.h"
-#include "rtc_base/deprecated/recursive_critical_section.h"
+#include "rtc_base/synchronization/sequence_checker.h"
 
 namespace webrtc {
 
@@ -58,13 +58,18 @@ class RtpStreamReceiverController
     RtpPacketSinkInterface* const sink_;
   };
 
-  // TODO(nisse): Move to a TaskQueue for synchronization. When used
-  // by Call, we expect construction and all methods but OnRtpPacket
-  // to be called on the same thread, and OnRtpPacket to be called
-  // by a single, but possibly distinct, thread. But applications not
-  // using Call may have use threads differently.
-  rtc::RecursiveCriticalSection lock_;
-  RtpDemuxer demuxer_ RTC_GUARDED_BY(&lock_);
+  // TODO(bugs.webrtc.org/11993): We expect construction and all methods to be
+  // called on the same thread/tq. Currently this is the worker thread
+  // (including OnRtpPacket) but a more natural fit would be the network thread.
+  // Using a sequence checker to ensure that usage is correct but at the same
+  // time not require a specific thread/tq, an instance of this class + the
+  // associated functionality should be easily moved from one execution context
+  // to another (i.e. when network packets don't hop to the worker thread inside
+  // of Call).
+  SequenceChecker demuxer_sequence_;
+  // At this level the demuxer is only configured to demux by SSRC, so don't
+  // worry about MIDs (MIDs are handled by upper layers).
+  RtpDemuxer demuxer_ RTC_GUARDED_BY(&demuxer_sequence_){false /*use_mid*/};
 };
 
 }  // namespace webrtc