Add SkImage::makeColorSpace() with correct transfer fn behavior

Completes implementation for lazy and raster images.  gpu is
still a TODO.

Bug: skia:6553
Change-Id: I04eea5c4fb53c50c0406c2e6b6778b0e21fd85f8
Reviewed-on: https://skia-review.googlesource.com/14403
Commit-Queue: Matt Sarett <msarett@google.com>
Reviewed-by: Mike Reed <reed@google.com>
37 files changed