Add AbsoluteCaptureTime RTP extension to supported list in engines.

Added as stopped by default as it should be requested by the application,
but it should be listed as available.

Bug: webrtc:14631
Change-Id: I301cfd29c79083c97b4a43b8fdafee2dbe4887a5
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/308824
Commit-Queue: Florent Castelli <orphis@webrtc.org>
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#40300}
diff --git a/media/engine/webrtc_video_engine.cc b/media/engine/webrtc_video_engine.cc
index 72a0f03..01eacb3 100644
--- a/media/engine/webrtc_video_engine.cc
+++ b/media/engine/webrtc_video_engine.cc
@@ -896,6 +896,9 @@
         webrtc::RtpExtension::kRidUri, webrtc::RtpExtension::kRepairedRidUri}) {
     result.emplace_back(uri, id++, webrtc::RtpTransceiverDirection::kSendRecv);
   }
+  for (const auto& uri : {webrtc::RtpExtension::kAbsoluteCaptureTimeUri}) {
+    result.emplace_back(uri, id++, webrtc::RtpTransceiverDirection::kStopped);
+  }
   result.emplace_back(webrtc::RtpExtension::kGenericFrameDescriptorUri00, id++,
                       IsEnabled(trials_, "WebRTC-GenericDescriptorAdvertised")
                           ? webrtc::RtpTransceiverDirection::kSendRecv
diff --git a/media/engine/webrtc_voice_engine.cc b/media/engine/webrtc_voice_engine.cc
index fd3a679..1ee0c21 100644
--- a/media/engine/webrtc_voice_engine.cc
+++ b/media/engine/webrtc_voice_engine.cc
@@ -37,6 +37,7 @@
 #include "api/media_types.h"
 #include "api/priority.h"
 #include "api/rtp_headers.h"
+#include "api/rtp_parameters.h"
 #include "api/rtp_transceiver_direction.h"
 #include "api/task_queue/pending_task_safety_flag.h"
 #include "api/transport/bitrate_settings.h"
@@ -684,6 +685,9 @@
                           webrtc::RtpExtension::kMidUri}) {
     result.emplace_back(uri, id++, webrtc::RtpTransceiverDirection::kSendRecv);
   }
+  for (const auto& uri : {webrtc::RtpExtension::kAbsoluteCaptureTimeUri}) {
+    result.emplace_back(uri, id++, webrtc::RtpTransceiverDirection::kStopped);
+  }
   return result;
 }