Get rid of the ZoneScopeMode.

src/zone.h

Index: src/zone.h
diff --git a/src/zone.h b/src/zone.h
index 128552a57a44c661fb7cb64b516b405e8e9f46d2..cc03254d1ed9146e3edbbfe30c034ff3f5a8a774 100644
--- a/src/zone.h
+++ b/src/zone.h
@@ -39,13 +39,6 @@ namespace v8 {
 namespace internal {
 
 
-// Zone scopes are in one of two modes.  Either they delete the zone
-// on exit or they do not.
-enum ZoneScopeMode {
-  DELETE_ON_EXIT,
-  DONT_DELETE_ON_EXIT
-};
-
 class Segment;
 class Isolate;
 
@@ -237,7 +230,7 @@ class ZoneList: public List<T, ZoneAllocationPolicy> {
 // outer-most scope.
 class ZoneScope BASE_EMBEDDED {
  public:
-  INLINE(ZoneScope(Zone* zone, ZoneScopeMode mode));
+  INLINE(ZoneScope(Zone* zone));
 
   virtual ~ZoneScope();
 
@@ -245,17 +238,10 @@ class ZoneScope BASE_EMBEDDED {
 
   inline bool ShouldDeleteOnExit();
 
-  // For ZoneScopes that do not delete on exit by default, call this
-  // method to request deletion on exit.
-  void DeleteOnExit() {
-    mode_ = DELETE_ON_EXIT;
-  }
-
   inline static int nesting();
 
  private:
   Zone* zone_;
-  ZoneScopeMode mode_;
 };