Fine-tune inobject slack tracking....

src/handles.cc

 // Copyright 2009 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 157 matching lines @@
   // If no properties are added in the constructor, they are more likely
   // to be added later.
   if (estimate == 0) estimate = 2;
 
   // We do not shrink objects that go into a snapshot (yet), so we adjust
   // the estimate conservatively.
   if (Serializer::enabled()) return estimate + 2;
 
   // Inobject slack tracking will reclaim redundant inobject space later,
   // so we can afford to adjust the estimate generously.
-  return estimate + 6;
+  return estimate + 8;
 }
 
 
 void SetExpectedNofPropertiesFromEstimate(Handle<SharedFunctionInfo> shared,
                                           int estimate) {
   // See the comment in SetExpectedNofProperties.
   if (shared->live_objects_may_exist()) return;
 
   shared->set_expected_nof_properties(
       ExpectedNofPropertiesFromEstimate(estimate));
@@ skipping 648 matching lines @@
 
 OptimizedObjectForAddingMultipleProperties::
 ~OptimizedObjectForAddingMultipleProperties() {
   // Reoptimize the object to allow fast property access.
   if (has_been_transformed_) {
     TransformToFastProperties(object_, unused_property_fields_);
   }
 }
 
 } }  // namespace v8::internal