Accept all the media profiles required by JSEP.

webrtc/pc/mediasession.cc

Index: webrtc/pc/mediasession.cc
diff --git a/webrtc/pc/mediasession.cc b/webrtc/pc/mediasession.cc
index 6b05736f0a3f3e74d662bb305e2458b7b7eba8ed..b077e0f83ff9e2146ebeb4a925764b3d2a379bff 100644
--- a/webrtc/pc/mediasession.cc
+++ b/webrtc/pc/mediasession.cc
@@ -1115,21 +1115,55 @@ static bool CreateMediaContentAnswer(
   return true;
 }
 
+static bool IsDtlsRtp(const std::string& protocol) {
+  // Most-likely values first.
+  return protocol == "UDP/TLS/RTP/SAVPF" || protocol == "TCP/TLS/RTP/SAVPF" ||
+         protocol == "UDP/TLS/RTP/SAVP" || protocol == "TCP/TLS/RTP/SAVP";
+}
+
+static bool IsPlainRtp(const std::string& protocol) {
+  // Most-likely values first.
+  return protocol == "RTP/SAVPF" || protocol == "RTP/AVPF" ||
+         protocol == "RTP/SAVP" || protocol == "RTP/AVP";
+}
+
+static bool IsDtlsSctp(const std::string& protocol) {
+  return protocol == "DTLS/SCTP";
+}
+
+static bool IsPlainSctp(const std::string& protocol) {
+  return protocol == "SCTP";
+}
+
 static bool IsMediaProtocolSupported(MediaType type,
                                      const std::string& protocol,
                                      bool secure_transport) {
-  // Data channels can have a protocol of SCTP or SCTP/DTLS.
-  if (type == MEDIA_TYPE_DATA &&
-      ((protocol == kMediaProtocolSctp && !secure_transport)||
-       (protocol == kMediaProtocolDtlsSctp && secure_transport))) {
+  // Since not all applications serialize and deserialize the media protocol,
+  // we will have to accept |protocol| to be empty.
+  if (protocol.empty()) {
     return true;
   }
 
-  // Since not all applications serialize and deserialize the media protocol,
-  // we will have to accept |protocol| to be empty.
-  return protocol == kMediaProtocolAvpf || protocol.empty() ||
-      protocol == kMediaProtocolSavpf ||
-      (protocol == kMediaProtocolDtlsSavpf && secure_transport);
+  if (type == MEDIA_TYPE_DATA) {
+    // Check for SCTP, but also for RTP for RTP-based data channels.
+    // TODO(pthatcher): Remove RTP once RTP-based data channels are gone.
+    if (secure_transport) {
+      // Most likely scenarios first.
+      return IsDtlsSctp(protocol) || IsDtlsRtp(protocol) ||
+             IsPlainRtp(protocol);
+    } else {
+      return IsPlainSctp(protocol) || IsPlainRtp(protocol);
+    }
+  }
+
+  // Allow for non-DTLS RTP protocol even when using DTLS because that's what
+  // JSEP specifies.
+  if (secure_transport) {
+    // Most likely scenarios first.
+    return IsDtlsRtp(protocol) || IsPlainRtp(protocol);
+  } else {
+    return IsPlainRtp(protocol);
+  }
 }
 
 static void SetMediaProtocol(bool secure_transport,