[PATCH 2/3] gdiplus: Convert gif frame to DIB on load

[Vincent Povirk]

I don't like that we essentially have another instance here of the
bitmap create/destroy logic. I think I'd rather we create another
bitmap than use the existing one with new image data.

It's not clear to me that decode_image_wic is even worth calling. Most
of the logic in there is for reading image bits, and couldn't we in
theory use blit_gif_frame or select_image_gif from the next patch for
that?

Or, if we wanted to add another hook to it, we could ask
decode_image_wic to not attempt to find a matching format, and instead
fall back on the conversion to 32bppARGB.