Roll recipe dependencies (trivial).

This is an automated CL created by the recipe roller. This CL rolls recipe
changes from upstream projects (build) into this repository.

build:
  https://crrev.com/f5bb258f4990967f0591563b79b78b2b089228ac (mbonadei@chromium.org)
    Increase xvfb -maxclients to 512.
  https://crrev.com/c6da2523af93f335c56a162616de24af4f4c237d (yekuang@google.com)
    [recipe] Use the 'swarming' recipe module to trigger tasks by default

More info is at https://goo.gl/zkKdpD. Use https://goo.gl/noib3a to file a bug.

TBR=keyonghan@google.com

Recipe-Tryjob-Bypass-Reason: Autoroller
Bugdroid-Send-Email: False
Change-Id: Ia663d9a71538f308cc0c8f92861631b9e55e5613
Reviewed-on: https://flutter-review.googlesource.com/c/recipes/+/8060
Reviewed-by: flutter-prod-builder@chops-service-accounts.iam.gserviceaccount.com <flutter-prod-builder@chops-service-accounts.iam.gserviceaccount.com>
Commit-Queue: flutter-prod-builder@chops-service-accounts.iam.gserviceaccount.com <flutter-prod-builder@chops-service-accounts.iam.gserviceaccount.com>
diff --git a/infra/config/recipes.cfg b/infra/config/recipes.cfg
index 986b920..399e8db 100644
--- a/infra/config/recipes.cfg
+++ b/infra/config/recipes.cfg
@@ -25,7 +25,7 @@
   "deps": {
     "build": {
       "branch": "refs/heads/master",
-      "revision": "d9cf9f65873308d70bfe91387d7a1aec7d17376d",
+      "revision": "c6da2523af93f335c56a162616de24af4f4c237d",
       "url": "https://chromium.googlesource.com/chromium/tools/build"
     },
     "depot_tools": {