Get rid of the ZoneScopeMode.

src/json-parser.h

Index: src/json-parser.h
diff --git a/src/json-parser.h b/src/json-parser.h
index 152bd637161a824d8aea9fac046498369419edb9..1e7ebd8c9eb5f5656349d95de41483b9b2fec661 100644
--- a/src/json-parser.h
+++ b/src/json-parser.h
@@ -323,7 +323,7 @@ Handle<Object> JsonParser<seq_ascii>::ParseJsonObject() {
   Handle<JSObject> json_object =
       factory()->NewJSObject(object_constructor(), pretenure_);
   Handle<Map> map(json_object->map());
-  ZoneScope zone_scope(zone(), DELETE_ON_EXIT);
+  ZoneScope zone_scope(zone());
   ZoneList<Handle<Object> > properties(8, zone());
   ASSERT_EQ(c0_, '{');
 
@@ -469,7 +469,7 @@ Handle<Object> JsonParser<seq_ascii>::ParseJsonObject() {
 template <bool seq_ascii>
 Handle<Object> JsonParser<seq_ascii>::ParseJsonArray() {
   HandleScope scope(isolate());
-  ZoneScope zone_scope(zone(), DELETE_ON_EXIT);
+  ZoneScope zone_scope(zone());
   ZoneList<Handle<Object> > elements(4, zone());
   ASSERT_EQ(c0_, '[');