autoroll: Reduce Tint->Dawn cooldown to 4h

Bug: None
Change-Id: I7e2ff7de52b434f183d2e1ed6f8844bee10f91c4
Reviewed-on: https://skia-review.googlesource.com/c/buildbot/+/398897
Auto-Submit: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Ben Clayton <bclayton@google.com>
Reviewed-by: Eric Boren <borenet@google.com>
Commit-Queue: Eric Boren <borenet@google.com>
diff --git a/autoroll/config/tint-dawn.cfg b/autoroll/config/tint-dawn.cfg
index 27a3ad9..2ff1553 100644
--- a/autoroll/config/tint-dawn.cfg
+++ b/autoroll/config/tint-dawn.cfg
@@ -11,7 +11,7 @@
 service_account:  "dawn-autoroll@skia-public.iam.gserviceaccount.com"
 reviewer:  "https://chrome-ops-rotation-proxy.appspot.com/current/grotation:webgpu-sheriff"
 reviewer_backup:  "radial-bots+tint-roll@google.com"
-roll_cooldown:  "24h"
+roll_cooldown:  "4h"
 commit_msg:  {
   bug_project:  "dawn"
   child_log_url_tmpl:  "https://dawn.googlesource.com/tint.git/+log/{{.RollingFrom}}..{{.RollingTo}}"