Roll recipe dependencies (trivial).

This is an automated CL created by the recipe roller. This CL rolls recipe
changes from upstream projects (e.g. depot_tools) into downstream projects
(e.g. tools/build).


More info is at https://goo.gl/zkKdpD. Use https://goo.gl/noib3a to file a bug.
depot_tools:
  https://crrev.com/6d31ed5d639e0bead9080b6543f8c1e6b69b0221 cpplint: Fix Python 3 errors. (ehmaldonado@google.com)


TBR=borenet@google.com

Recipe-Tryjob-Bypass-Reason: Autoroller
Bugdroid-Send-Email: False
Change-Id: I8594a8acc84a2180f3647012571d247e8fa2a856
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/257536
Reviewed-by: Recipe Roller <recipe-mega-autoroller@chops-service-accounts.iam.gserviceaccount.com>
Commit-Queue: Recipe Roller <recipe-mega-autoroller@chops-service-accounts.iam.gserviceaccount.com>
diff --git a/infra/config/recipes.cfg b/infra/config/recipes.cfg
index 1b1f06f..b98db26 100644
--- a/infra/config/recipes.cfg
+++ b/infra/config/recipes.cfg
@@ -14,7 +14,7 @@
   "deps": {
     "depot_tools": {
       "branch": "master",
-      "revision": "02b5af35755b90057b87f48afe9d7faa1de5d97f",
+      "revision": "6d31ed5d639e0bead9080b6543f8c1e6b69b0221",
       "url": "https://chromium.googlesource.com/chromium/tools/depot_tools.git"
     },
     "recipe_engine": {