name types in skcms.h

The typedefs make code read pretty,
but having names too should allow forward declaration.

Change-Id: I5b1c3e468f332f7267a294184f48a0da8fcdccff
Reviewed-on: https://skia-review.googlesource.com/121788
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
1 file changed