use VectorValue consistently

Bug: skia:
Change-Id: I148bd0cac3c094b30217b30104ebbc6e080c994f
Reviewed-on: https://skia-review.googlesource.com/145885
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Mike Reed <reed@google.com>
1 file changed