[webkit-dev] Why the limited scope for preferredExtensionForImageSourceType?

[Brent Fulgham]

A recent change added some tests in the dragging logic for valid file
extension.  The default Cairo implementation was set to return blank,
which causes these various assertions to fire, rendering these
operations unusable.

It seems that most of the information necessary to determine expected
file extension is present in the various decoders, but the mapping
from UTI's to extensions was implemented deep in the guts of
ImageSourceCGWin, rather than at some higher level.

Is the "preferredExtensionForImageSourceType" function really Windows
and CG-specific?  These types and UTI's seem like they should be
generally applicable.

I would like to move this to at least ImageSource.cpp, so that the
Cairo back-end could make use of the mapping.

Does anyone know why the scope of this function was limited so severely?

Thanks,

-Brent