tools/gn: Update docs to refer to 'public_configs'.

'direct_dependent_configs' is the deprecated name and should not be used
anymore.

BUG=None
R=dpranke@chromium.org

Review URL: https://codereview.chromium.org/1190393003

Cr-Original-Commit-Position: refs/heads/master@{#335280}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 634ad43fed1e67462429f1e94ec7a4c1c85c0444
1 file changed
tree: b04552eba6ec52171498698ba8a6b5af537e0284
  1. tools/