LibWeb: Begin implementing media resource seeking

Author: https://github.com/trflynn89
Commit: 5a98a5529f
Pull-request: https://github.com/SerenityOS/serenity/pull/18296
Reviewed-by: https://github.com/Zaggy1024 ✅

Userland/Libraries/LibWeb/HTML/HTMLVideoElement.cpp

@@ -101,4 +101,10 @@ void HTMLVideoElement::on_paused()
         m_video_track->pause_video({});
 }
 
+void HTMLVideoElement::on_seek(double position, MediaSeekMode seek_mode)
+{
+    if (m_video_track)
+        m_video_track->seek(Time::from_milliseconds(position * 1000.0), seek_mode);
+}
+
 }