skip transfer functions when not needed

Change-Id: I72e1084e6a14b3c1fa3f0a5c2100f13c6bcb24c7
Reviewed-on: https://skia-review.googlesource.com/130062
Commit-Queue: Mike Klein <mtklein@chromium.org>
Auto-Submit: Mike Klein <mtklein@chromium.org>
Reviewed-by: Brian Osman <brianosman@google.com>
3 files changed