Activate pubsub for dart masters

masters/master.client.dart/master.cfg

Index: masters/master.client.dart/master.cfg
diff --git a/masters/master.client.dart/master.cfg b/masters/master.client.dart/master.cfg
index a77447a7d3130a4996b91379927e6e539bad01c4..afb967a2eb392ef725c5b04c9559207e6e41f5d9 100644
--- a/masters/master.client.dart/master.cfg
+++ b/masters/master.client.dart/master.cfg
@@ -17,6 +17,7 @@ from master import build_utils
 from master import master_utils
 from master import slaves_list
 from master import status_logger
+from master import pubsub_json_status_push
 from master.factory import annotator_factory
 from master.factory.dart import dart_factory
 from master.factory.dart.dart_factory import (linux_env, windows_env,
@@ -598,6 +599,15 @@ c['prioritizeBuilders'] = utils.prioritize_builders
 
 c['status'] = [status_logger.StatusEventLogger()]
 
+# Add in the pubsub pusher, which pushes all status updates to a pubsub
+# topic.  This will not run unless is_production_host is set to True.
+# This will fail on a production host if it cannot find the service
+# account file.
+pubsub_pusher = pubsub_json_status_push.StatusPush.CreateStatusPush(
+    activeMaster=ActiveMaster)
+if pubsub_pusher:
+  c['status'].append(pubsub_pusher)
+
 if WEB_STATUS:
   for status in utils.get_web_statuses():
     c['status'].append(status)