Add SkColorSpace::isNumericalTransferFn() to the public API

This adds a little more flexibility for clients wanting to handle
color space transformation outside of the codecs.  Ex: they can
leave the encoded data as is and apply the numerical transfer
fn in a later step.

BUG=skia:

Change-Id: Ieca53b01648d4cb9cf0995715deacd4c4876900f
Reviewed-on: https://skia-review.googlesource.com/9077
Reviewed-by: Mike Reed <reed@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Matt Sarett <msarett@google.com>
2 files changed