infra: Add mixins for using RBE prod cluster

Since we cannot combine mixins, these mixins contain the different
combinations that we will use.

R=tikuta@chromium.org, ukai@chromium.org, yyanagisawa@chromium.org

Bug: 913249
Change-Id: Ic5efaba32650173f6a1905903ec8a2ac116a7d83
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1598898Reviewed-by: Takuto Ikuta <tikuta@chromium.org>
Commit-Queue: Simon Que <sque@chromium.org>
Cr-Commit-Position: refs/heads/master@{#657643}

infra/config/cr-buildbucket.cfg

@@ -159,6 +159,19 @@ builder_mixins {
   }
 }
 
+# Enables use of Goma RBE Prod backend in a builder.
+builder_mixins {
+  name: "goma-rbe-prod"
+  recipe {
+    properties_j: <<END
+    $build/goma: {
+      "server_host": "goma.chromium.org",
+      "rpc_extra_params": "?prod"
+    }
+    END
+  }
+}
+
 builder_mixins {
   name: "android"
   dimensions: "os:Android"
@@ -2747,21 +2760,25 @@ buckets {
       name: "Chromium Linux Goma RBE Prod"
       dimensions: "os:Ubuntu-14.04"
       mixins: "goma-ci"
+      mixins: "goma-rbe-prod"
     }
     builders {
       name: "Chromium Linux Goma RBE Prod (clobber)"
       dimensions: "os:Ubuntu-14.04"
       mixins: "goma-ci"
+      mixins: "goma-rbe-prod"
     }
     builders {
       name: "Chromium Linux Goma RBE Prod (dbg)"
       dimensions: "os:Ubuntu-14.04"
       mixins: "goma-ci"
+      mixins: "goma-rbe-prod"
     }
     builders {
       name: "Chromium Linux Goma RBE Prod (dbg) (clobber)"
       dimensions: "os:Ubuntu-14.04"
       mixins: "goma-ci"
+      mixins: "goma-rbe-prod"
     }
     builders {
       name: "Chromium Linux Goma RBE LoadTest"
@@ -2877,21 +2894,25 @@ buckets {
       name: "Chromium Android ARM 32-bit Goma RBE Prod"
       dimensions: "os:Ubuntu-14.04"
       mixins: "goma-ci"
+      mixins: "goma-rbe-prod"
     }
     builders {
       name: "Chromium Android ARM 32-bit Goma RBE Prod (clobber)"
       dimensions: "os:Ubuntu-14.04"
       mixins: "goma-ci"
+      mixins: "goma-rbe-prod"
     }
     builders {
       name: "Chromium Android ARM 32-bit Goma RBE Prod (dbg)"
       dimensions: "os:Ubuntu-14.04"
       mixins: "goma-ci"
+      mixins: "goma-rbe-prod"
     }
     builders {
       name: "Chromium Android ARM 32-bit Goma RBE Prod (dbg) (clobber)"
       dimensions: "os:Ubuntu-14.04"
       mixins: "goma-ci"
+      mixins: "goma-rbe-prod"
     }
     builders {
       name: "Chromium Android ARM 32-bit Goma RBE LoadTest"