Add commit queue settings to Dart

tools/infra/config/cq.cfg

 # See http://luci-config.appspot.com/schemas/projects/refs:cq.cfg for the
 # documentation of this file format.
 version: 1
 cq_name: "dart"
 cq_status_url: "https://chromium-cq-status.appspot.com"
-git_repo_url: "https://dart.googlesource.com/sdk.git"
+git_repo_url: "https://github.com/dart-lang/sdk.git"

[tandrii(chromium), 2017/08/21 15:24:06]

this won't work. This is gerrit CQ, not a Rietveld one, and Gerrit CQ needs a
Gerrit host here.

[Bill Hesse, 2017/08/21 15:26:40]

OK, I saw in an earlier post on the gob->github sync issue, and in the
go/we-need-cq, that groups were managing to make cq commit to github from their
gerrit reviews.  Is there no way to make Gerrit commit to Github?

 gerrit { }
 verifiers {
   gerrit_cq_ability {
      committer_list: "project-dart-committers"
      dry_run_access_list: "project-dart-tryjob-access"
   }
   try_job {
     buckets {
       name: "luci.dart.try"
-      builders { name: "vm-win-debug-x64-try"}
-      builders { name: "vm-win-release-x64-try"}
-      builders { name: "vm-linux-debug-x64-try"}
+      builders { name: "analyzer-linux-release-strong-try"}
       builders { name: "vm-linux-release-x64-try"}
-      builders { name: "vm-mac-debug-x64-try"}
-      builders { name: "vm-mac-release-x64-try"}
-      builders { name: "dart2js-linux-d8-hostchecked-unittest-try"}
-      builders { name: "analyzer-linux-release-strong-try"}
+      builders { name: "vm-win-release-x64-try"
+                 experiment_percentage: 100.0}
+      builders { name: "vm-mac-release-x64-try"
+                 experiment_percentage: 100.0}
+      builders { name: "dart2js-linux-d8-hostchecked-unittest-try"
+                 experiment_percentage: 100.0}
+      builders { name: "pkg-linux-release-try"
+                 experiment_percentage: 100.0}
     }
   }
 }