Interface RTCRtpReceiver and RTCPeerConnection.getReceivers() added.

third_party/WebKit/Source/modules/peerconnection/RTCPeerConnection.cpp

Index: third_party/WebKit/Source/modules/peerconnection/RTCPeerConnection.cpp
diff --git a/third_party/WebKit/Source/modules/peerconnection/RTCPeerConnection.cpp b/third_party/WebKit/Source/modules/peerconnection/RTCPeerConnection.cpp
index fcea99b69faf1737293ee78a5592fd1dcd3292d2..8fc04a166a886ab81982056e33ed999281faf830 100644
--- a/third_party/WebKit/Source/modules/peerconnection/RTCPeerConnection.cpp
+++ b/third_party/WebKit/Source/modules/peerconnection/RTCPeerConnection.cpp
@@ -32,6 +32,7 @@
 
 #include <algorithm>
 #include <memory>
+#include <set>
 #include "bindings/core/v8/ExceptionMessages.h"
 #include "bindings/core/v8/ExceptionState.h"
 #include "bindings/core/v8/Microtask.h"
@@ -67,6 +68,7 @@
 #include "modules/peerconnection/RTCOfferOptions.h"
 #include "modules/peerconnection/RTCPeerConnectionErrorCallback.h"
 #include "modules/peerconnection/RTCPeerConnectionIceEvent.h"
+#include "modules/peerconnection/RTCRtpReceiver.h"
 #include "modules/peerconnection/RTCSessionDescription.h"
 #include "modules/peerconnection/RTCSessionDescriptionCallback.h"
 #include "modules/peerconnection/RTCSessionDescriptionInit.h"
@@ -1179,6 +1181,30 @@ ScriptPromise RTCPeerConnection::getStats(ScriptState* scriptState) {
   return promise;
 }
 
+HeapVector<Member<RTCRtpReceiver>> RTCPeerConnection::getReceivers() {
+  WebVector<std::unique_ptr<WebRTCRtpReceiver>> webRtpReceivers =
+      m_peerHandler->getReceivers();
+  HeapVector<Member<RTCRtpReceiver>> rtpReceivers(webRtpReceivers.size());
+  for (size_t i = 0; i < webRtpReceivers.size(); ++i) {
+    uintptr_t id = webRtpReceivers[i]->id();
+    const auto it = m_rtpReceivers.find(id);
+    if (it != m_rtpReceivers.end()) {
+      rtpReceivers[i] = it->value;
+    } else {
+      // There does not exist a JavaScript |RTCRtpReceiver| for this

[foolip, 2017/03/29 10:07:58]

The RTCRtpReceiver is still not the JavaScript object, there's an additional
V8RTCRtpReceiver wrapping it and then I'm not sure if there's another layer
before we get real to JavaScript objects or not. No mention of JavaScript here
is probably best :)

[hbos_chromium, 2017/03/29 13:50:13]

Done.

+      // |WebRTCRtpReceiver| yet, create it.
+      MediaStreamTrack* track =
+          getRemoteTrackById(webRtpReceivers[i]->track().id());
+      DCHECK(track);
+      RTCRtpReceiver* rtpReceiver =
+          new RTCRtpReceiver(std::move(webRtpReceivers[i]), track);
+      m_rtpReceivers.insert(id, rtpReceiver);
+      rtpReceivers[i] = rtpReceiver;
+    }
+  }
+  return rtpReceivers;
+}
+
 RTCDataChannel* RTCPeerConnection::createDataChannel(
     ScriptState* scriptState,
     String label,
@@ -1234,6 +1260,29 @@ bool RTCPeerConnection::hasLocalStreamWithTrackId(const String& trackId) {
   return false;
 }
 
+MediaStreamTrack* RTCPeerConnection::getRemoteTrackById(
+    const String& trackId) const {
+  for (const auto& remoteStream : m_remoteStreams) {
+    MediaStreamTrack* track = remoteStream->getTrackById(trackId);
+    if (track)
+      return track;
+  }
+  return nullptr;
+}
+
+void RTCPeerConnection::removeInactiveReceivers() {
+  std::set<uintptr_t> inactiveReceiverIds;
+  for (uintptr_t id : m_rtpReceivers.keys()) {
+    inactiveReceiverIds.insert(id);
+  }
+  for (const auto& webRtpReceiver : m_peerHandler->getReceivers()) {
+    inactiveReceiverIds.erase(webRtpReceiver->id());
+  }
+  for (uintptr_t id : inactiveReceiverIds) {
+    m_rtpReceivers.erase(id);
+  }
+}
+
 RTCDTMFSender* RTCPeerConnection::createDTMFSender(
     MediaStreamTrack* track,
     ExceptionState& exceptionState) {
@@ -1333,6 +1382,9 @@ void RTCPeerConnection::didRemoveRemoteStream(
   DCHECK(pos != kNotFound);
   m_remoteStreams.remove(pos);
 
+  // The receivers of removed tracks will have become inactive.
+  removeInactiveReceivers();
+
   scheduleDispatchEvent(
       MediaStreamEvent::create(EventTypeNames::removestream, stream));
 }
@@ -1505,6 +1557,7 @@ void RTCPeerConnection::recordRapporMetrics() {
 DEFINE_TRACE(RTCPeerConnection) {
   visitor->trace(m_localStreams);
   visitor->trace(m_remoteStreams);
+  visitor->trace(m_rtpReceivers);
   visitor->trace(m_dispatchScheduledEventRunner);
   visitor->trace(m_scheduledEvents);
   EventTargetWithInlineData::trace(visitor);