This directory contains the HarfBuzz source from the upstream repo:
https://github.com/harfbuzz/harfbuzz

Current version: 2.3.1 [commit 55d1d7c8bcd8d97c4e618e5dd21f13df50b10ce8]

UPDATING:

Our in-tree copy of HarfBuzz does not depend on any generated files from the
upstream build system. Therefore, it should be sufficient to simply overwrite
the in-tree files one the updated ones from upstream to perform updates.

To simplify this, the in-tree copy can be updated by running
  sh update.sh
from within the gfx/harfbuzz directory.

If the collection of source files changes, manual updates to moz.build may be
needed as we don't use the upstream makefiles.
