Add Serializable attributes to encoded video frames

Fixes: 181

Author: alvestrand

index.bs

@@ -381,7 +381,7 @@ dictionary RTCEncodedVideoFrameMetadata {
 <pre class="idl">
 // New interfaces to define encoded video and audio frames. Will eventually
 // re-use or extend the equivalent defined in WebCodecs.
-[Exposed=(Window,DedicatedWorker)]
+[Exposed=(Window,DedicatedWorker), Serializable]
 interface RTCEncodedVideoFrame {
     readonly attribute RTCEncodedVideoFrameType type;
     readonly attribute unsigned long timestamp;
@@ -487,7 +487,7 @@ dictionary RTCEncodedAudioFrameMetadata {
 
 ## <dfn interface>RTCEncodedAudioFrame</dfn> interface ## {#RTCEncodedAudioFrame-interface}
 <pre class="idl">
-[Exposed=(Window,DedicatedWorker)]
+[Exposed=(Window,DedicatedWorker), Serializable]
 interface RTCEncodedAudioFrame {
     readonly attribute unsigned long timestamp;
     attribute ArrayBuffer data;