Optimize stroke tessellation patch allocation

This speeds up the microbench by ~20% (620us -> 502).

Bug: chromium:1172543
Change-Id: I926db1d8eec9bbf053cc3379053424f79aea3445
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/373763
Reviewed-by: John Stiles <johnstiles@google.com>
Commit-Queue: Chris Dalton <csmartdalton@google.com>
1 file changed