Use SK_ALWAYS_INLINE in SkColorSpaceXform

Two reasons for this:
(1) We care about the performance of this code, and Windows isn't
very good at inlining.  Let's make sure we isntruct the compiler
to inline.
(2) Since landing uses of this in Chrome, we're seeing flaky
LayoutTests that appear to be timing related.  I'm (very
optimistically) hoping that this will help.

BUG=skia:

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=3744

Change-Id: Ibb6d9c4252c0b8ce62203fe65c7dd296248982c8
Reviewed-on: https://skia-review.googlesource.com/3744
Commit-Queue: Matt Sarett <msarett@google.com>
Reviewed-by: Mike Klein <mtklein@chromium.org>
1 file changed