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/e9730d75a00548a22e4392567243969d85c02dd4 subprocess2: Ensure environment keys and values are strings on Python 3 (raul@tambre.ee)


TBR=borenet@google.com

Recipe-Tryjob-Bypass-Reason: Autoroller
Bugdroid-Send-Email: False
Change-Id: I66b2e976e6c8e1f94094dd663040277aa2660d28
Reviewed-on: https://skia-review.googlesource.com/c/buildbot/+/264638
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 9c3600a..b1ba052 100644
--- a/infra/config/recipes.cfg
+++ b/infra/config/recipes.cfg
@@ -14,7 +14,7 @@
   "deps": {
     "depot_tools": {
       "branch": "master",
-      "revision": "2a04803267c61a53e9769bb2963b45e06a981804",
+      "revision": "e9730d75a00548a22e4392567243969d85c02dd4",
       "url": "https://chromium.googlesource.com/chromium/tools/depot_tools.git"
     },
     "recipe_engine": {