Reland of cq.cfg: add equivalent builder for LUCI linux_chromium_rel_ng.

Previously
  Landed on: https://chromium-review.googlesource.com/539615
  Reverted on: https://chromium-review.googlesource.com/540981

R=estaab@chromium.org, sergiyb@chromium.org

Bug: 
Change-Id: I3001ae9f704ead3d1ed42e6cb049778813c8879b
No-Try: True
Reviewed-on: https://chromium-review.googlesource.com/541217
Reviewed-by: Sergiy Byelozyorov <sergiyb@chromium.org>
Commit-Queue: Andrii Shyshkalov <tandrii@chromium.org>
Cr-Commit-Position: refs/heads/master@{#480794}

infra/config/cq.cfg

@@ -59,8 +59,18 @@ verifiers {
       #builders { name: "linux_chromium_clobber_rel_ng" }
       builders { name: "linux_chromium_compile_dbg_ng" }
       builders { name: "linux_chromium_headless_rel" }
-      builders { name: "linux_chromium_rel_ng" }
       builders { name: "linux_chromium_tsan_rel_ng" }
+      builders {
+        name: "linux_chromium_rel_ng"
+        equivalent_to {
+          # Builders in this bucket are defined in
+          # https://chromium.googlesource.com/chromium/src/+/infra/config/cr-buildbucket.cfg
+          bucket: "luci.chromium.try"
+          builder: "LUCI linux_chromium_rel_ng"
+          owner_whitelist_group: "luci-chromium-cq-dogfood"
+          percentage: 100
+        }
+      }
     }
     buckets {
       name: "master.tryserver.chromium.mac"