The classes Image and BitmapImage are overloaded with many other functions. The platform-specific format conversion is not tied to BitmapImage or Image. It relies mostly on NativeImages. So move the format conversion to a new class named ImageAdapter. Move also BitmapImage::nativeImageOfSize() and BitmapImage::framesNativeImages() to this new class since they are only used by the format conversion.
<rdar://problem/120690546>
Pull request: https://github.com/WebKit/WebKit/pull/22535
Committed 273772@main (ab92c87e9f99): <https://commits.webkit.org/273772@main> Reviewed commits have been landed. Closing PR #22535 and removing active labels.