Remove enabled features flag for DTLS and SCTP transports

Removes the RTCDtlsTransport and RTCSctpTransport features.
These have been "stable" since May 2019.

Bug: chromium:944027
Change-Id: I47d5aec2d7551980734fb1f13abd26d41955eeb4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2120579
Auto-Submit: Harald Alvestrand <hta@chromium.org>
Reviewed-by: Guido Urdaneta <guidou@chromium.org>
Reviewed-by: Philip Jägenstedt <foolip@chromium.org>
Commit-Queue: Philip Jägenstedt <foolip@chromium.org>
Cr-Commit-Position: refs/heads/master@{#753602}

third_party/blink/renderer/modules/peerconnection/rtc_dtls_transport.idl

@@ -13,8 +13,7 @@ enum RTCDtlsTransportState {
 };
 
 [
-    Exposed=Window,
-    RuntimeEnabled=RTCDtlsTransport
+    Exposed=Window
 ] interface RTCDtlsTransport : EventTarget {
     readonly attribute RTCIceTransport iceTransport;
     readonly attribute RTCDtlsTransportState state;

third_party/blink/renderer/modules/peerconnection/rtc_peer_connection.idl

@@ -157,7 +157,7 @@ enum RTCPeerConnectionState {
     attribute EventHandler ontrack;
 
     // https://w3c.github.io/webrtc-pc/#peer-to-peer-data-api
-    [RuntimeEnabled=RTCSctpTransport] readonly attribute RTCSctpTransport? sctp;
+    readonly attribute RTCSctpTransport? sctp;
     [CallWith=ScriptState, RaisesException] RTCDataChannel createDataChannel(USVString label, optional RTCDataChannelInit dataChannelDict = {});
     attribute EventHandler ondatachannel;
 

third_party/blink/renderer/modules/peerconnection/rtc_rtp_receiver.idl

@@ -6,8 +6,8 @@
 [Exposed=Window]
 interface RTCRtpReceiver {
     readonly attribute MediaStreamTrack track;
-    [RuntimeEnabled=RTCDtlsTransport] readonly attribute RTCDtlsTransport? transport;
-    [RuntimeEnabled=RTCDtlsTransport] readonly attribute RTCDtlsTransport? rtcpTransport;
+    readonly attribute RTCDtlsTransport? transport;
+    readonly attribute RTCDtlsTransport? rtcpTransport;
     // https://henbos.github.io/webrtc-extensions/#dom-rtcrtpreceiver-playoutdelayhint
     [RaisesException=Setter, Measure] attribute double? playoutDelayHint;
     static RTCRtpCapabilities?            getCapabilities(DOMString kind);

third_party/blink/renderer/modules/peerconnection/rtc_rtp_sender.idl

@@ -6,8 +6,8 @@
 [Exposed=Window]
 interface RTCRtpSender {
     readonly attribute MediaStreamTrack? track;
-    [RuntimeEnabled=RTCDtlsTransport] readonly attribute RTCDtlsTransport? transport;
-    [RuntimeEnabled=RTCDtlsTransport] readonly attribute RTCDtlsTransport? rtcpTransport;
+    readonly attribute RTCDtlsTransport? transport;
+    readonly attribute RTCDtlsTransport? rtcpTransport;
     static RTCRtpCapabilities? getCapabilities(DOMString kind);
     [CallWith=ScriptState] Promise<void> setParameters(optional RTCRtpSendParameters parameters = {});
     RTCRtpSendParameters getParameters();

third_party/blink/renderer/modules/peerconnection/rtc_sctp_transport.idl

@@ -12,8 +12,7 @@ enum RTCSctpTransportState {
 // http://w3c.github.io/webrtc-pc/#rtcdtlstransport-interface
 
 [
-    Exposed=Window,
-    RuntimeEnabled=RTCSctpTransport
+    Exposed=Window
 ] interface RTCSctpTransport : EventTarget {
     readonly        attribute RTCDtlsTransport transport;
     readonly        attribute RTCSctpTransportState state;

third_party/blink/renderer/platform/runtime_enabled_features.json5

@@ -1454,11 +1454,6 @@
       origin_trial_feature_name: "RtcAudioJitterBufferRtxHandling",
       status: "experimental",
     },
-    // Enables the use of the RTCDtlsTransport object.
-    {
-      name: "RTCDtlsTransport",
-      status: "stable",
-    },
     // Enables the use of the RTCIceTransport with extensions.
     {
       name: "RTCIceTransportExtension",
@@ -1477,11 +1472,6 @@
       origin_trial_feature_name: "RTCQuicTransport",
       status: "experimental",
     },
-    // Enables the use of the RTCSctpTransport object.
-    {
-      name: "RTCSctpTransport",
-      status: "stable",
-    },
     {
       name: "RTCStatsRelativePacketArrivalDelay",
       origin_trial_feature_name: "RTCStatsRelativePacketArrivalDelay",