Merge pull request #8959 from maralorn/print-parent

Print parent activity field in json log

src/libutil/logging.cc

@@ -220,8 +220,8 @@ struct JSONLogger : Logger {
         json["level"] = lvl;
         json["type"] = type;
         json["text"] = s;
+        json["parent"] = parent;
         addFields(json, fields);
-        // FIXME: handle parent
         write(json);
     }