Update URI of TransportSequenceNumberV2

The previous URI was a placeholder and is not valid. The URI
https://webrtc.org/experiments/rtp-hdrext/transport-wide-cc-02/
must be used instead.

Bug: webrtc:10264
Change-Id: Ibabde599b5bbd116c1c5e86ba0c9c64019bf7026
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/126360
Reviewed-by: Danil Chapovalov <danilchap@webrtc.org>
Reviewed-by: Per Kjellander <perkj@webrtc.org>
Commit-Queue: Johannes Kron <kron@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#27051}
diff --git a/api/rtp_parameters.cc b/api/rtp_parameters.cc
index 6177dd3..9ba2423 100644
--- a/api/rtp_parameters.cc
+++ b/api/rtp_parameters.cc
@@ -105,7 +105,7 @@
 const char RtpExtension::kTransportSequenceNumberUri[] =
     "http://www.ietf.org/id/draft-holmer-rmcat-transport-wide-cc-extensions-01";
 const char RtpExtension::kTransportSequenceNumberV2Uri[] =
-    "http://www.ietf.org/id/draft-holmer-rmcat-transport-wide-cc-extensions-02";
+    "http://www.webrtc.org/experiments/rtp-hdrext/transport-wide-cc-02";
 
 // This extension allows applications to adaptively limit the playout delay
 // on frames as per the current needs. For example, a gaming application
diff --git a/modules/rtp_rtcp/source/rtp_header_extensions.h b/modules/rtp_rtcp/source/rtp_header_extensions.h
index e36c83f..8aacb9a 100644
--- a/modules/rtp_rtcp/source/rtp_header_extensions.h
+++ b/modules/rtp_rtcp/source/rtp_header_extensions.h
@@ -97,8 +97,7 @@
   static constexpr uint8_t kValueSizeBytes = 4;
   static constexpr uint8_t kValueSizeBytesWithoutFeedbackRequest = 2;
   static constexpr const char kUri[] =
-      "http://www.ietf.org/id/"
-      "draft-holmer-rmcat-transport-wide-cc-extensions-02";
+      "http://www.webrtc.org/experiments/rtp-hdrext/transport-wide-cc-02";
   static bool Parse(rtc::ArrayView<const uint8_t> data,
                     uint16_t* transport_sequence_number,
                     absl::optional<FeedbackRequest>* feedback_request);
diff --git a/pc/media_session.cc b/pc/media_session.cc
index ca4434e..8377f10 100644
--- a/pc/media_session.cc
+++ b/pc/media_session.cc
@@ -1113,7 +1113,7 @@
         // Don't respond to
         // http://www.ietf.org/id/draft-holmer-rmcat-transport-wide-cc-extensions-01
         // if we get an offer including
-        // http://www.ietf.org/id/draft-holmer-rmcat-transport-wide-cc-extensions-02
+        // http://www.webrtc.org/experiments/rtp-hdrext/transport-wide-cc-02
         continue;
       } else {
         // We respond with their RTP header extension id.
diff --git a/pc/media_session_unittest.cc b/pc/media_session_unittest.cc
index e876c36..7c0a7de 100644
--- a/pc/media_session_unittest.cc
+++ b/pc/media_session_unittest.cc
@@ -223,15 +223,15 @@
     RtpExtension("http://www.ietf.org/id/"
                  "draft-holmer-rmcat-transport-wide-cc-extensions-01",
                  1),
-    RtpExtension("http://www.ietf.org/id/"
-                 "draft-holmer-rmcat-transport-wide-cc-extensions-02",
-                 2),
+    RtpExtension(
+        "http://www.webrtc.org/experiments/rtp-hdrext/transport-wide-cc-02",
+        2),
 };
 
 static const RtpExtension kRtpExtensionTransportSequenceNumber02[] = {
-    RtpExtension("http://www.ietf.org/id/"
-                 "draft-holmer-rmcat-transport-wide-cc-extensions-02",
-                 2),
+    RtpExtension(
+        "http://www.webrtc.org/experiments/rtp-hdrext/transport-wide-cc-02",
+        2),
 };
 
 static const uint32_t kSimulcastParamsSsrc[] = {10, 11, 20, 21, 30, 31};