Add experimental Swarmbucket bot

infra/project-config/cr-buildbucket.cfg

 # Defines buckets on cr-buildbucket.appspot.com, used to schedule builds
 # on buildbot. In particular, CQ uses some of these buckets to schedule tryjobs.
 #
 # See http://luci-config.appspot.com/schemas/projects:buildbucket.cfg for
 # schema of this file and documentation.
 #
 # Please keep this list sorted by bucket name.
 
 buckets {
   name: "master.client.skia"
@@ skipping 66 matching lines @@
     group: "project-skia-tryjob-access"
   }
   acls {
     role: SCHEDULER
     group: "service-account-cq"
   }
   acls {
     role: WRITER
     group: "service-account-skia-master"
   }
+
+  swarming {
+    hostname: "chromium-swarm.appspot.com"
+    common_dimensions {
+      key: "pool"
+      value: "Skia"
+    }
+    common_swarming_tags: "master:master.client.skia.fyi"
+    builders {
+      name: "Build-Ubuntu-GCC-x86_64-Release-Swarmbucket"
+      swarming_tags: "builder:Build-Ubuntu-GCC-x86_64-Release-Swarmbucket"

[nodir, 2016/03/22 17:13:59]

I'd recommend to set "builder" tag in buildbucket build, so it is easier to
search for builds by builder name in
https://apis-explorer.appspot.com/apis-explorer/?base=https://cr-buildbucket....
Buildbucket tags are automatically included in swarming tags

+      dimensions {
+        key: "os"
+        value: "Linux"
+      }
+      recipe {
+        repository: "https://chromium.googlesource.com/chromium/tools/build"
+        name: "skia/skia"
+      }
+    }
+  }
 }