Merge "ChangeJson: add Javadoc"

java/com/google/gerrit/server/change/ChangeJson.java

diff --git a/java/com/google/gerrit/server/change/ChangeJson.java b/java/com/google/gerrit/server/change/ChangeJson.java
index 300a32d..3d350b0 100644
--- a/java/com/google/gerrit/server/change/ChangeJson.java
+++ b/java/com/google/gerrit/server/change/ChangeJson.java
@@ -160,6 +160,12 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+/**
+ * Produces {@link ChangeInfo} (which is serialized to JSON afterwards) from {@link ChangeData}.
+ *
+ * <p>This is intended to be used on request scope, but may be used for converting multiple {@link
+ * ChangeData} objects from different sources.
+ */
 public class ChangeJson {
   private static final Logger log = LoggerFactory.getLogger(ChangeJson.class);