Drawable: Use the Read/WriteBuffer bulk API for points

Change-Id: Id64ad7369f16f2388a4320586b9b30c7c9cc82c0
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/566558
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Herb Derby <herb@google.com>
1 file changed