Merge branch 'stable-3.9' into stable-3.10

* stable-3.9:
  Bind Gson.class as Singleton in EventBroker

Release-Notes: skip
Change-Id: I0481de4f84683dab250cd29c273ea7d41bac669c

java/com/google/gerrit/server/events/EventBroker.java

diff --git a/java/com/google/gerrit/server/events/EventBroker.java b/java/com/google/gerrit/server/events/EventBroker.java
index 2697da5..71256bd 100644
--- a/java/com/google/gerrit/server/events/EventBroker.java
+++ b/java/com/google/gerrit/server/events/EventBroker.java
@@ -52,7 +52,10 @@
       DynamicItem.itemOf(binder(), EventDispatcher.class);
       DynamicItem.bind(binder(), EventDispatcher.class).to(EventBroker.class);
 
-      bind(Gson.class).annotatedWith(EventGson.class).toProvider(EventGsonProvider.class);
+      bind(Gson.class)
+          .annotatedWith(EventGson.class)
+          .toProvider(EventGsonProvider.class)
+          .in(Singleton.class);
     }
   }