Make harfbuzz not use mutexes, since we only layout on
UI task runner.

Change-Id: I24cadbf4000e0fa2f69361dea907416e39c5cf0c
Reviewed-on: https://fuchsia-review.googlesource.com/c/third_party/harfbuzz/+/415794
Reviewed-by: Chinmay Garde <chinmaygarde@google.com>
1 file changed