Temporarily disabling JSON generation for Zone statistics to resolve flakiness in tests until a bet…

runtime/observatory/lib/src/service/object.dart

Index: runtime/observatory/lib/src/service/object.dart
diff --git a/runtime/observatory/lib/src/service/object.dart b/runtime/observatory/lib/src/service/object.dart
index 1618aedd72a8a7e600190283279ba0613ab17e22..8f82cd18dba65007c6bac7bb53831417e786e382 100644
--- a/runtime/observatory/lib/src/service/object.dart
+++ b/runtime/observatory/lib/src/service/object.dart
@@ -3114,7 +3114,6 @@ class Thread extends ServiceObject implements M.Thread {
 
   void _update(Map map, bool mapIsRef) {
     String rawKind = map['kind'];
-    List<Map> zoneList = map['zones'];
 
     switch(rawKind) {
       case "kUnknownTask":
@@ -3146,13 +3145,6 @@ class Thread extends ServiceObject implements M.Thread {
     }
 
     _memoryHighWatermark = int.parse(map['_memoryHighWatermark']);
-
-    zones.clear();
-    zoneList.forEach((zone) {
-      int capacity = zone['capacity'];
-      int used = zone['used'];
-      zones.add(new Zone(capacity, used));
-    });
   }
 }