Roll gn from 693f9fb87e4f to 79c6c1b1a24c

https://gn.googlesource.com/gn.git/+log/693f9fb87e4f..79c6c1b1a24c

2021-10-26 brettw@chromium.org Add a FAQ entry on directory copying.

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/gn-chromium-autoroll
Please CC dpranke@chromium.org,thakis@chromium.org on the revert to ensure that a human
is aware of the problem.

To file a bug in Chromium: https://bugs.chromium.org/p/chromium/issues/entry

To report a problem with the AutoRoller itself, please file a bug:
https://bugs.chromium.org/p/skia/issues/entry?template=Autoroller+Bug

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+doc/main/autoroll/README.md

Tbr: dpranke@chromium.org,thakis@chromium.org
Change-Id: I192717e9466bb43d8638426cdd6cf7c9ff714cd3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3245272
Commit-Queue: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
Bot-Commit: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
Reviewed-by: Dirk Pranke <dpranke@google.com>
Cr-Commit-Position: refs/heads/main@{#935104}

DEPS

@@ -416,7 +416,7 @@ vars = {
   'libcxx_revision':       '79a2e924d96e2fc1e4b937c42efd08898fa472d7',
 
   # GN CIPD package version.
-  'gn_version': 'git_revision:693f9fb87e4febdd4299db9f73d8d2c958e63148',
+  'gn_version': 'git_revision:79c6c1b1a24c46df5a773cc61604bb5051ca6cf4',
 }
 
 # Only these hosts are allowed for dependencies in this DEPS file.