don't call mutex if we're unique

Takes the overhead of invoking the Editor down to near 0. This affects
every call to SkPath for adding segments (e.g. moveTo, lineTo).

10% faster for rotated drawAtlas

Change-Id: Ice66fc78042429dc545e597a352195cf1ce54187
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/239918
Reviewed-by: Ben Wagner <bungeman@google.com>
Commit-Queue: Mike Reed <reed@google.com>
1 file changed