Remove make_signature, use enums for all ICC signatures

Expose the data and profile connection space values, for use by clients

Change-Id: Ie258ece9158c466a6326ddbd754e6078929678f0
Reviewed-on: https://skia-review.googlesource.com/126481
Auto-Submit: Brian Osman <brianosman@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>
3 files changed