Add Store3 to Sk2f

Bug: skia:
Change-Id: I0377e6a1dd8259e944f7902a5c68af524fa588c7
Reviewed-on: https://skia-review.googlesource.com/79382
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Chris Dalton <csmartdalton@google.com>
4 files changed