Remove unused IsDirty

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index 811ad746e23f24f3611a1da7cde93cd1779f9c40..47a61f627b817ca7d533aea305cfde7b90e4d110 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -731,21 +731,6 @@ Handle<Object> JSObject::DeleteNormalizedProperty(Handle<JSObject> object,
 }
 
 
-bool JSObject::IsDirty() {
-  Object* cons_obj = map()->constructor();
-  if (!cons_obj->IsJSFunction())
-    return true;
-  JSFunction* fun = JSFunction::cast(cons_obj);
-  if (!fun->shared()->IsApiFunction())
-    return true;
-  // If the object is fully fast case and has the same map it was
-  // created with then no changes can have been made to it.
-  return map() != fun->initial_map()
-      || !HasFastObjectElements()
-      || !HasFastProperties();
-}
-
-
 MaybeHandle<Object> Object::GetElementWithReceiver(Isolate* isolate,
                                                    Handle<Object> object,
                                                    Handle<Object> receiver,