fix skipT to use sizeof T

Bug: skia:
Change-Id: Ifd6d3cfc4499afda763353ceaeecbbb28a97ff2c
Reviewed-on: https://skia-review.googlesource.com/90265
Reviewed-by: Mike Reed <reed@google.com>
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Mike Reed <reed@google.com>
1 file changed