Add fast path to SkColorSpaceXformSteps

No need to do any real work if the src and dst are identical

Change-Id: I46dd21ed6464e9ffcbf07434e696f16b85f3193b
Reviewed-on: https://skia-review.googlesource.com/153006
Commit-Queue: Brian Osman <brianosman@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
Auto-Submit: Brian Osman <brianosman@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>
1 file changed