Introduce RtpStreamReceiverInterface and RtpStreamReceiverControllerInterface.

And implementation class RtpStreamReceiverController.
It's responsible for demuxing, and acts as factory for
RtpStreamReceiverInterface.

BUG=webrtc:7135

Review-Url: https://codereview.webrtc.org/2886993005
Cr-Commit-Position: refs/heads/master@{#18696}
diff --git a/webrtc/call/BUILD.gn b/webrtc/call/BUILD.gn
index 9807c64..aa98053 100644
--- a/webrtc/call/BUILD.gn
+++ b/webrtc/call/BUILD.gn
@@ -38,6 +38,7 @@
 rtc_source_set("rtp_interfaces") {
   sources = [
     "rtp_packet_sink_interface.h",
+    "rtp_stream_receiver_controller_interface.h",
     "rtp_transport_controller_send_interface.h",
   ]
 }
@@ -46,6 +47,8 @@
   sources = [
     "rtp_demuxer.cc",
     "rtp_demuxer.h",
+    "rtp_stream_receiver_controller.cc",
+    "rtp_stream_receiver_controller.h",
     "rtx_receive_stream.cc",
     "rtx_receive_stream.h",
   ]
diff --git a/webrtc/call/call.cc b/webrtc/call/call.cc
index c0861dd..b4a9456 100644
--- a/webrtc/call/call.cc
+++ b/webrtc/call/call.cc
@@ -34,7 +34,7 @@
 #include "webrtc/call/bitrate_allocator.h"
 #include "webrtc/call/call.h"
 #include "webrtc/call/flexfec_receive_stream_impl.h"
-#include "webrtc/call/rtp_demuxer.h"
+#include "webrtc/call/rtp_stream_receiver_controller.h"
 #include "webrtc/call/rtp_transport_controller_send.h"
 #include "webrtc/config.h"
 #include "webrtc/logging/rtc_event_log/rtc_event_log.h"
@@ -275,10 +275,10 @@
   std::map<std::string, AudioReceiveStream*> sync_stream_mapping_
       GUARDED_BY(receive_crit_);
 
-  // TODO(nisse): Should eventually be part of injected
-  // RtpTransportControllerReceive, with a single demuxer in the bundled case.
-  RtpDemuxer audio_rtp_demuxer_ GUARDED_BY(receive_crit_);
-  RtpDemuxer video_rtp_demuxer_ GUARDED_BY(receive_crit_);
+  // TODO(nisse): Should eventually be injected at creation,
+  // with a single object in the bundled case.
+  RtpStreamReceiverController audio_receiver_controller;
+  RtpStreamReceiverController video_receiver_controller;
 
   // This extra map is used for receive processing which is
   // independent of media type.
@@ -486,10 +486,6 @@
   if (!parsed_packet.Parse(packet, length))
     return rtc::Optional<RtpPacketReceived>();
 
-  auto it = receive_rtp_config_.find(parsed_packet.Ssrc());
-  if (it != receive_rtp_config_.end())
-    parsed_packet.IdentifyExtensions(it->second.extensions);
-
   int64_t arrival_time_ms;
   if (packet_time && packet_time->timestamp != -1) {
     arrival_time_ms = (packet_time->timestamp + 500) / 1000;
@@ -646,12 +642,11 @@
   TRACE_EVENT0("webrtc", "Call::CreateAudioReceiveStream");
   RTC_DCHECK_RUN_ON(&configuration_thread_checker_);
   event_log_->LogAudioReceiveStreamConfig(CreateRtcLogStreamConfig(config));
-  AudioReceiveStream* receive_stream =
-      new AudioReceiveStream(transport_send_->packet_router(), config,
-                             config_.audio_state, event_log_);
+  AudioReceiveStream* receive_stream = new AudioReceiveStream(
+      &audio_receiver_controller, transport_send_->packet_router(), config,
+      config_.audio_state, event_log_);
   {
     WriteLockScoped write_lock(*receive_crit_);
-    audio_rtp_demuxer_.AddSink(config.rtp.remote_ssrc, receive_stream);
     receive_rtp_config_[config.rtp.remote_ssrc] =
         ReceiveRtpConfig(config.rtp.extensions, UseSendSideBwe(config));
     audio_receive_streams_.insert(receive_stream);
@@ -683,8 +678,6 @@
     uint32_t ssrc = config.rtp.remote_ssrc;
     receive_side_cc_.GetRemoteBitrateEstimator(UseSendSideBwe(config))
         ->RemoveStream(ssrc);
-    size_t num_deleted = audio_rtp_demuxer_.RemoveSink(audio_receive_stream);
-    RTC_DCHECK(num_deleted == 1);
     audio_receive_streams_.erase(audio_receive_stream);
     const std::string& sync_group = audio_receive_stream->config().sync_group;
     const auto it = sync_stream_mapping_.find(sync_group);
@@ -776,19 +769,17 @@
   TRACE_EVENT0("webrtc", "Call::CreateVideoReceiveStream");
   RTC_DCHECK_RUN_ON(&configuration_thread_checker_);
 
-  VideoReceiveStream* receive_stream =
-      new VideoReceiveStream(num_cpu_cores_, transport_send_->packet_router(),
-                             std::move(configuration),
-                             module_process_thread_.get(), call_stats_.get());
+  VideoReceiveStream* receive_stream = new VideoReceiveStream(
+      &video_receiver_controller, num_cpu_cores_,
+      transport_send_->packet_router(), std::move(configuration),
+      module_process_thread_.get(), call_stats_.get());
 
   const webrtc::VideoReceiveStream::Config& config = receive_stream->config();
   ReceiveRtpConfig receive_config(config.rtp.extensions,
                                   UseSendSideBwe(config));
   {
     WriteLockScoped write_lock(*receive_crit_);
-    video_rtp_demuxer_.AddSink(config.rtp.remote_ssrc, receive_stream);
     if (config.rtp.rtx_ssrc) {
-      video_rtp_demuxer_.AddSink(config.rtp.rtx_ssrc, receive_stream);
       // We record identical config for the rtx stream as for the main
       // stream. Since the transport_send_cc negotiation is per payload
       // type, we may get an incorrect value for the rtx stream, but
@@ -817,8 +808,6 @@
     WriteLockScoped write_lock(*receive_crit_);
     // Remove all ssrcs pointing to a receive stream. As RTX retransmits on a
     // separate SSRC there can be either one or two.
-    size_t num_deleted = video_rtp_demuxer_.RemoveSink(receive_stream_impl);
-    RTC_DCHECK_GE(num_deleted, 1);
     receive_rtp_config_.erase(config.rtp.remote_ssrc);
     if (config.rtp.rtx_ssrc) {
       receive_rtp_config_.erase(config.rtp.rtx_ssrc);
@@ -840,16 +829,22 @@
   RTC_DCHECK_RUN_ON(&configuration_thread_checker_);
 
   RecoveredPacketReceiver* recovered_packet_receiver = this;
-  FlexfecReceiveStreamImpl* receive_stream = new FlexfecReceiveStreamImpl(
-      config, recovered_packet_receiver, call_stats_->rtcp_rtt_stats(),
-      module_process_thread_.get());
 
+  FlexfecReceiveStreamImpl* receive_stream;
   {
     WriteLockScoped write_lock(*receive_crit_);
-    video_rtp_demuxer_.AddSink(config.remote_ssrc, receive_stream);
-
-    for (auto ssrc : config.protected_media_ssrcs)
-      video_rtp_demuxer_.AddSink(ssrc, receive_stream);
+    // Unlike the video and audio receive streams,
+    // FlexfecReceiveStream implements RtpPacketSinkInterface itself,
+    // and hence its constructor passes its |this| pointer to
+    // video_receiver_controller->CreateStream(). Calling the
+    // constructor while holding |receive_crit_| ensures that we don't
+    // call OnRtpPacket until the constructor is finished and the
+    // object is in a valid state.
+    // TODO(nisse): Fix constructor so that it can be moved outside of
+    // this locked scope.
+    receive_stream = new FlexfecReceiveStreamImpl(
+        &video_receiver_controller, config, recovered_packet_receiver,
+        call_stats_->rtcp_rtt_stats(), module_process_thread_.get());
 
     RTC_DCHECK(receive_rtp_config_.find(config.remote_ssrc) ==
                receive_rtp_config_.end());
@@ -881,7 +876,6 @@
 
     // Remove all SSRCs pointing to the FlexfecReceiveStreamImpl to be
     // destroyed.
-    video_rtp_demuxer_.RemoveSink(receive_stream_impl);
     receive_side_cc_.GetRemoteBitrateEstimator(UseSendSideBwe(config))
         ->RemoveStream(ssrc);
   }
@@ -1302,17 +1296,31 @@
   if (!parsed_packet)
     return DELIVERY_PACKET_ERROR;
 
+  auto it = receive_rtp_config_.find(parsed_packet->Ssrc());
+  if (it == receive_rtp_config_.end()) {
+    LOG(LS_ERROR) << "receive_rtp_config_ lookup failed for ssrc "
+                  << parsed_packet->Ssrc();
+    // Destruction of the receive stream, including deregistering from the
+    // RtpDemuxer, is not protected by the |receive_crit_| lock. But
+    // deregistering in the |receive_rtp_config_| map is protected by that lock.
+    // So by not passing the packet on to demuxing in this case, we prevent
+    // incoming packets to be passed on via the demuxer to a receive stream
+    // which is being torned down.
+    return DELIVERY_UNKNOWN_SSRC;
+  }
+  parsed_packet->IdentifyExtensions(it->second.extensions);
+
   NotifyBweOfReceivedPacket(*parsed_packet, media_type);
 
   if (media_type == MediaType::AUDIO) {
-    if (audio_rtp_demuxer_.OnRtpPacket(*parsed_packet)) {
+    if (audio_receiver_controller.OnRtpPacket(*parsed_packet)) {
       received_bytes_per_second_counter_.Add(static_cast<int>(length));
       received_audio_bytes_per_second_counter_.Add(static_cast<int>(length));
       event_log_->LogRtpHeader(kIncomingPacket, packet, length);
       return DELIVERY_OK;
     }
   } else if (media_type == MediaType::VIDEO) {
-    if (video_rtp_demuxer_.OnRtpPacket(*parsed_packet)) {
+    if (video_receiver_controller.OnRtpPacket(*parsed_packet)) {
       received_bytes_per_second_counter_.Add(static_cast<int>(length));
       received_video_bytes_per_second_counter_.Add(static_cast<int>(length));
       event_log_->LogRtpHeader(kIncomingPacket, packet, length);
@@ -1348,7 +1356,7 @@
 
   parsed_packet->set_recovered(true);
 
-  video_rtp_demuxer_.OnRtpPacket(*parsed_packet);
+  video_receiver_controller.OnRtpPacket(*parsed_packet);
 }
 
 void Call::NotifyBweOfReceivedPacket(const RtpPacketReceived& packet,
diff --git a/webrtc/call/flexfec_receive_stream_impl.cc b/webrtc/call/flexfec_receive_stream_impl.cc
index f010433..c73d9e9 100644
--- a/webrtc/call/flexfec_receive_stream_impl.cc
+++ b/webrtc/call/flexfec_receive_stream_impl.cc
@@ -15,6 +15,7 @@
 #include "webrtc/base/checks.h"
 #include "webrtc/base/location.h"
 #include "webrtc/base/logging.h"
+#include "webrtc/call/rtp_stream_receiver_controller_interface.h"
 #include "webrtc/modules/rtp_rtcp/include/flexfec_receiver.h"
 #include "webrtc/modules/rtp_rtcp/include/receive_statistics.h"
 #include "webrtc/modules/rtp_rtcp/include/rtp_rtcp.h"
@@ -122,6 +123,7 @@
 }  // namespace
 
 FlexfecReceiveStreamImpl::FlexfecReceiveStreamImpl(
+    RtpStreamReceiverControllerInterface* receiver_controller,
     const Config& config,
     RecoveredPacketReceiver* recovered_packet_receiver,
     RtcpRttStats* rtt_stats,
@@ -141,6 +143,22 @@
   rtp_rtcp_->SetRTCPStatus(config_.rtcp_mode);
   rtp_rtcp_->SetSSRC(config_.local_ssrc);
   process_thread_->RegisterModule(rtp_rtcp_.get(), RTC_FROM_HERE);
+
+  // Register with transport.
+  // TODO(nisse): OnRtpPacket in this class delegates all real work to
+  // |receiver_|. So maybe we don't need to implement RtpPacketSinkInterface
+  // here at all, we'd then delete the OnRtpPacket method and instead register
+  // |receiver_| as the RtpPacketSinkInterface for this stream.
+  // TODO(nisse): Passing |this| from the constructor to the RtpDemuxer, before
+  // the object is fully initialized, is risky. But it works in this case
+  // because locking in our caller, Call::CreateFlexfecReceiveStream, ensures
+  // that the demuxer doesn't call OnRtpPacket before this object is fully
+  // constructed. Registering |receiver_| instead of |this| would solve this
+  // problem too.
+  rtp_stream_receiver_ =
+      receiver_controller->CreateReceiver(config_.remote_ssrc, this);
+  for (uint32_t ssrc : config.protected_media_ssrcs)
+    receiver_controller->AddSink(ssrc, this);
 }
 
 FlexfecReceiveStreamImpl::~FlexfecReceiveStreamImpl() {
diff --git a/webrtc/call/flexfec_receive_stream_impl.h b/webrtc/call/flexfec_receive_stream_impl.h
index e4c2294..a89940f 100644
--- a/webrtc/call/flexfec_receive_stream_impl.h
+++ b/webrtc/call/flexfec_receive_stream_impl.h
@@ -26,14 +26,18 @@
 class RtcpRttStats;
 class RtpPacketReceived;
 class RtpRtcp;
+class RtpStreamReceiverControllerInterface;
+class RtpStreamReceiverInterface;
 
 class FlexfecReceiveStreamImpl : public FlexfecReceiveStream,
                                  public RtpPacketSinkInterface {
  public:
-  FlexfecReceiveStreamImpl(const Config& config,
-                           RecoveredPacketReceiver* recovered_packet_receiver,
-                           RtcpRttStats* rtt_stats,
-                           ProcessThread* process_thread);
+  FlexfecReceiveStreamImpl(
+      RtpStreamReceiverControllerInterface* receiver_controller,
+      const Config& config,
+      RecoveredPacketReceiver* recovered_packet_receiver,
+      RtcpRttStats* rtt_stats,
+      ProcessThread* process_thread);
   ~FlexfecReceiveStreamImpl() override;
 
   const Config& GetConfig() const { return config_; }
@@ -59,6 +63,8 @@
   const std::unique_ptr<ReceiveStatistics> rtp_receive_statistics_;
   const std::unique_ptr<RtpRtcp> rtp_rtcp_;
   ProcessThread* process_thread_;
+
+  std::unique_ptr<RtpStreamReceiverInterface> rtp_stream_receiver_;
 };
 
 }  // namespace webrtc
diff --git a/webrtc/call/flexfec_receive_stream_unittest.cc b/webrtc/call/flexfec_receive_stream_unittest.cc
index 46bd7c3..ba41406 100644
--- a/webrtc/call/flexfec_receive_stream_unittest.cc
+++ b/webrtc/call/flexfec_receive_stream_unittest.cc
@@ -12,6 +12,7 @@
 
 #include "webrtc/base/array_view.h"
 #include "webrtc/call/flexfec_receive_stream_impl.h"
+#include "webrtc/call/rtp_stream_receiver_controller.h"
 #include "webrtc/modules/pacing/packet_router.h"
 #include "webrtc/modules/rtp_rtcp/include/flexfec_receiver.h"
 #include "webrtc/modules/rtp_rtcp/mocks/mock_recovered_packet_receiver.h"
@@ -77,7 +78,8 @@
  protected:
   FlexfecReceiveStreamTest()
       : config_(CreateDefaultConfig(&rtcp_send_transport_)),
-        receive_stream_(config_,
+        receive_stream_(&rtp_stream_receiver_controller_,
+                        config_,
                         &recovered_packet_receiver_,
                         &rtt_stats_,
                         &process_thread_) {}
@@ -87,7 +89,7 @@
   MockRecoveredPacketReceiver recovered_packet_receiver_;
   MockRtcpRttStats rtt_stats_;
   MockProcessThread process_thread_;
-
+  RtpStreamReceiverController rtp_stream_receiver_controller_;
   FlexfecReceiveStreamImpl receive_stream_;
 };
 
@@ -134,7 +136,8 @@
   // clang-format on
 
   testing::StrictMock<MockRecoveredPacketReceiver> recovered_packet_receiver;
-  FlexfecReceiveStreamImpl receive_stream(config_, &recovered_packet_receiver,
+  FlexfecReceiveStreamImpl receive_stream(&rtp_stream_receiver_controller_,
+                                          config_, &recovered_packet_receiver,
                                           &rtt_stats_, &process_thread_);
 
   // Do not call back before being started.
diff --git a/webrtc/call/rtp_stream_receiver_controller.cc b/webrtc/call/rtp_stream_receiver_controller.cc
new file mode 100644
index 0000000..a4b1e36
--- /dev/null
+++ b/webrtc/call/rtp_stream_receiver_controller.cc
@@ -0,0 +1,58 @@
+/*
+ *  Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/call/rtp_stream_receiver_controller.h"
+#include "webrtc/base/ptr_util.h"
+
+namespace webrtc {
+
+RtpStreamReceiverController::Receiver::Receiver(
+    RtpStreamReceiverController* controller,
+    uint32_t ssrc,
+    RtpPacketSinkInterface* sink)
+    : controller_(controller), sink_(sink) {
+  controller_->AddSink(ssrc, sink_);
+}
+
+RtpStreamReceiverController::Receiver::~Receiver() {
+  // Don't require return value > 0, since for RTX we currently may
+  // have multiple Receiver objects with the same sink.
+  // TODO(nisse): Consider adding a DCHECK when RtxReceiveStream is wired up.
+  controller_->RemoveSink(sink_);
+}
+
+RtpStreamReceiverController::RtpStreamReceiverController() = default;
+RtpStreamReceiverController::~RtpStreamReceiverController() = default;
+
+std::unique_ptr<RtpStreamReceiverInterface>
+RtpStreamReceiverController::CreateReceiver(
+    uint32_t ssrc,
+    RtpPacketSinkInterface* sink) {
+  return rtc::MakeUnique<Receiver>(this, ssrc, sink);
+}
+
+bool RtpStreamReceiverController::OnRtpPacket(const RtpPacketReceived& packet) {
+  rtc::CritScope cs(&lock_);
+  return demuxer_.OnRtpPacket(packet);
+}
+
+void RtpStreamReceiverController::AddSink(uint32_t ssrc,
+                                          RtpPacketSinkInterface* sink) {
+  rtc::CritScope cs(&lock_);
+  return demuxer_.AddSink(ssrc, sink);
+}
+
+size_t RtpStreamReceiverController::RemoveSink(
+    const RtpPacketSinkInterface* sink) {
+  rtc::CritScope cs(&lock_);
+  return demuxer_.RemoveSink(sink);
+}
+
+}  // namespace webrtc
diff --git a/webrtc/call/rtp_stream_receiver_controller.h b/webrtc/call/rtp_stream_receiver_controller.h
new file mode 100644
index 0000000..5c8ed67
--- /dev/null
+++ b/webrtc/call/rtp_stream_receiver_controller.h
@@ -0,0 +1,72 @@
+/*
+ *  Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+#ifndef WEBRTC_CALL_RTP_STREAM_RECEIVER_CONTROLLER_H_
+#define WEBRTC_CALL_RTP_STREAM_RECEIVER_CONTROLLER_H_
+
+#include <memory>
+
+#include "webrtc/base/criticalsection.h"
+#include "webrtc/call/rtp_demuxer.h"
+#include "webrtc/call/rtp_stream_receiver_controller_interface.h"
+
+namespace webrtc {
+
+class RtpPacketReceived;
+
+// This class represents the RTP receive parsing and demuxing, for a
+// single RTP session.
+// TODO(nisse): Add RTCP processing, we should aim to terminate RTCP
+// and not leave any RTCP processing to individual receive streams.
+// TODO(nisse): Extract per-packet processing, including parsing and
+// demuxing, into a separate class.
+class RtpStreamReceiverController
+    : public RtpStreamReceiverControllerInterface {
+ public:
+  RtpStreamReceiverController();
+  ~RtpStreamReceiverController() override;
+
+  // Implements RtpStreamReceiverControllerInterface.
+  std::unique_ptr<RtpStreamReceiverInterface> CreateReceiver(
+      uint32_t ssrc,
+      RtpPacketSinkInterface* sink) override;
+
+  // Thread-safe wrappers for the corresponding RtpDemuxer methods.
+  void AddSink(uint32_t ssrc, RtpPacketSinkInterface* sink) override;
+  size_t RemoveSink(const RtpPacketSinkInterface* sink) override;
+
+  // TODO(nisse): Not yet responsible for parsing.
+  bool OnRtpPacket(const RtpPacketReceived& packet);
+
+ private:
+  class Receiver : public RtpStreamReceiverInterface {
+   public:
+    Receiver(RtpStreamReceiverController* controller,
+             uint32_t ssrc,
+             RtpPacketSinkInterface* sink);
+
+    ~Receiver() override;
+
+   private:
+    RtpStreamReceiverController* const controller_;
+    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::CriticalSection lock_;
+  RtpDemuxer demuxer_ GUARDED_BY(&lock_);
+};
+
+}  // namespace webrtc
+
+#endif  // WEBRTC_CALL_RTP_STREAM_RECEIVER_CONTROLLER_H_
diff --git a/webrtc/call/rtp_stream_receiver_controller_interface.h b/webrtc/call/rtp_stream_receiver_controller_interface.h
new file mode 100644
index 0000000..51d25a5
--- /dev/null
+++ b/webrtc/call/rtp_stream_receiver_controller_interface.h
@@ -0,0 +1,47 @@
+/*
+ *  Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+#ifndef WEBRTC_CALL_RTP_STREAM_RECEIVER_CONTROLLER_INTERFACE_H_
+#define WEBRTC_CALL_RTP_STREAM_RECEIVER_CONTROLLER_INTERFACE_H_
+
+#include <memory>
+
+#include "webrtc/call/rtp_packet_sink_interface.h"
+
+namespace webrtc {
+
+// An RtpStreamReceiver is responsible for the rtp-specific but
+// media-independent state needed for receiving an RTP stream.
+// TODO(nisse): Currently, only owns the association between ssrc and
+// the stream's RtpPacketSinkInterface. Ownership of corresponding
+// objects from modules/rtp_rtcp/ should move to this class (or
+// rather, the corresponding implementation class). We should add
+// methods for getting rtp receive stats, and for sending RTCP
+// messages related to the receive stream.
+class RtpStreamReceiverInterface {
+ public:
+  virtual ~RtpStreamReceiverInterface() {}
+};
+
+// This class acts as a factory for RtpStreamReceiver objects.
+class RtpStreamReceiverControllerInterface {
+ public:
+  virtual ~RtpStreamReceiverControllerInterface() {}
+
+  virtual std::unique_ptr<RtpStreamReceiverInterface> CreateReceiver(
+      uint32_t ssrc,
+      RtpPacketSinkInterface* sink) = 0;
+  // For registering additional sinks, needed for FlexFEC.
+  virtual void AddSink(uint32_t ssrc, RtpPacketSinkInterface* sink) = 0;
+  virtual size_t RemoveSink(const RtpPacketSinkInterface* sink) = 0;
+};
+
+}  // namespace webrtc
+
+#endif  // WEBRTC_CALL_RTP_STREAM_RECEIVER_CONTROLLER_INTERFACE_H_