The files in this directory, except for src/, boringssl_dart.gyp, and
boringssl_configurations.gypi, are generated from the checkout of
boringssl in src/, by running the script
src/util/generate_build_files.py chromium.

That script is maintained by the chromium team, to make a gyp build
of boringssl that does not require go or perl.  We modify the main
gyp file of this build, boringssl.gyp, to add configurations for
the target architectures, creating boringssl_dart.gyp.

When updating boringssl in Dart, delete this directory,
and check out the new boringssl to src.  Then run the script, check out
our two files boringssl_dart.gyp and boringssl_configurations.gypi and commit
the changes and any added or deleted files, as well as a change to the
boringssl revision in DEPS.  If there are changes in boringssl.gyp,
consider making  similar changes to boringssl_dart.gyp
Test the changes on all platforms before committing, of course.