From Bug 35333, interesting comments especially in https://bugs.webkit.org/show_bug.cgi?id=35333#c8 and https://bugs.webkit.org/show_bug.cgi?id=35333#c10
I will send a patch to make PlatformMedia a typedef. As I think we agreed with Eric (correct me if I'm wrong!) it doesn't make much sense for it to be a structure.
Created attachment 55533 [details] proposed patch
Phillipe, please take a look at the patch in https://bugs.webkit.org/show_bug.cgi?id=38689. Windows WebCore now has multiple MediaPlayerPrivate engines created at runtime, each which needs to return a different type of PlatformMedia. Defining these types at compile-time by platform doesn't allow this. But adding a GStreamer specific type to the struct in the patch above would be very simple.
Ah well... then I guess I should mark this bug as invalid. For GStreamer the PlatformMedia stuff doesn't help much. I plan to propose a new API in the MediaPlayer to enter/exit fullscreen. The player would provide to the "client" a PlatformFullscreenWindow pointer. Anyway this is for another bug :)