[GStreamer][MediaStream][Westeros] Enable 'immediate-output' on streaming through westerossink

https://bugs.webkit.org/show_bug.cgi?id=259930

Reviewed by Philippe Normand.

https://bugs.webkit.org/show_bug.cgi?id=259357 removed the configuration of the "immediate-output" property for westeros sink, but it's still needed for mediastream content.

Original author: Vivek.A <Vivek_Arumugam@comcast.com>
See: #1136

* Source/WebCore/platform/graphics/gstreamer/MediaPlayerPrivateGStreamer.cpp:
(WebCore::MediaPlayerPrivateGStreamer::configureElementPlatformQuirks): Configure the immediate-output property for westerossink.

Canonical link: https://commits.webkit.org/266720@main

Author: eocanha

Source/WebCore/platform/graphics/gstreamer/MediaPlayerPrivateGStreamer.cpp

@@ -2303,6 +2303,13 @@ void MediaPlayerPrivateGStreamer::configureElementPlatformQuirks(GstElement* ele
 #endif
 #endif
 
+#if ENABLE(MEDIA_STREAM)
+    if (m_streamPrivate && !g_strcmp0(G_OBJECT_TYPE_NAME(G_OBJECT(element)), "GstWesterosSink") && gstObjectHasProperty(element, "immediate-output")) {
+        GST_DEBUG_OBJECT(pipeline(), "Enable 'immediate-output' in WesterosSink");
+        g_object_set(element, "immediate-output", TRUE, nullptr);
+    }
+#endif
+
 #if ENABLE(MEDIA_STREAM) && PLATFORM(REALTEK)
     if (m_streamPrivate) {
         if (gstObjectHasProperty(element, "media-tunnel")) {