[Object.observe] Don't force normalization of elements for observed objects

src/objects-inl.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 3631 matching lines @@
 void Map::set_owns_descriptors(bool is_shared) {
   set_bit_field3(OwnsDescriptors::update(bit_field3(), is_shared));
 }
 
 
 bool Map::owns_descriptors() {
   return OwnsDescriptors::decode(bit_field3());
 }
 
 
-void Map::set_is_observed(bool is_observed) {
-  ASSERT(instance_type() < FIRST_JS_OBJECT_TYPE ||
-         instance_type() > LAST_JS_OBJECT_TYPE ||
-         has_slow_elements_kind() || has_external_array_elements());
-  set_bit_field3(IsObserved::update(bit_field3(), is_observed));
+void Map::set_has_instance_call_handler() {
+  set_bit_field3(HasInstanceCallHandler::update(bit_field3(), true));
 }
 
 
-bool Map::is_observed() {
-  return IsObserved::decode(bit_field3());
+bool Map::has_instance_call_handler() {
+  return HasInstanceCallHandler::decode(bit_field3());
 }
 
 
 void Map::deprecate() {
   set_bit_field3(Deprecated::update(bit_field3(), true));
 }
 
 
 bool Map::is_deprecated() {
   if (!FLAG_track_fields) return false;
@@ skipping 2738 matching lines @@
 #undef WRITE_UINT32_FIELD
 #undef READ_SHORT_FIELD
 #undef WRITE_SHORT_FIELD
 #undef READ_BYTE_FIELD
 #undef WRITE_BYTE_FIELD
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_INL_H_