Renable traffic to mac coverage builder.

Also setting builderless to False, so that dedicated machines would be useed

Bug: 1024915
Change-Id: I4e3b3fb134f8ddbb354c7ec44614f77c9cf7de89
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2392166Reviewed-by: Erik Staab <estaab@chromium.org>
Commit-Queue: Prakhar Asthana <pasthana@google.com>
Auto-Submit: Prakhar Asthana <pasthana@google.com>
Cr-Commit-Position: refs/heads/master@{#804320}

infra/config/generated/commit-queue.cfg

@@ -1257,7 +1257,10 @@ config_groups {
       }
       builders {
         name: "chromium/try/mac-coverage-rel"
-        includable_only: true
+        experiment_percentage: 3
+        location_regexp: ".*"
+        location_regexp_exclude: ".+/[+]/docs/.+"
+        location_regexp_exclude: ".+/[+]/infra/config/.+"
       }
       builders {
         name: "chromium/try/mac-dawn-rel"

infra/config/generated/cq-builders.md

@@ -366,3 +366,6 @@ as required builders.
   * [`//content/browser/tracing/.+`](https://cs.chromium.org/chromium/src/content/browser/tracing/)
   * [`//services/tracing/.+`](https://cs.chromium.org/chromium/src/services/tracing/)
 
+* [mac-coverage-rel](https://ci.chromium.org/p/chromium/builders/try/mac-coverage-rel) ([definition](https://cs.chromium.org/search?q=package:%5Echromium$+file:/cq.star$+-file:/beta/+-file:/stable/+mac-coverage-rel)) ([matching builders](https://cs.chromium.org/search?q=+file:trybots.py+mac-coverage-rel))
+  * Experiment percentage: 3
+

infra/config/generated/cr-buildbucket.cfg

@@ -24985,7 +24985,7 @@ buckets {
       name: "mac-coverage-rel"
       swarming_host: "chromium-swarm.appspot.com"
       swarming_tags: "vpython:native-python-wrapper"
-      dimensions: "builderless:1"
+      dimensions: "builder:mac-coverage-rel"
       dimensions: "cpu:x86-64"
       dimensions: "os:Mac"
       dimensions: "pool:luci.chromium.try"

infra/config/subprojects/chromium/try.star

@@ -1086,8 +1086,10 @@ try_.chromium_linux_builder(
 
 try_.chromium_mac_builder(
     name = "mac-coverage-rel",
+    builderless = False,
     use_clang_coverage = True,
     goma_jobs = goma.jobs.J150,
+    tryjob = try_.job(experiment_percentage = 3),
 )
 
 try_.chromium_mac_builder(