| Index: src/flag-definitions.h
 | 
| diff --git a/src/flag-definitions.h b/src/flag-definitions.h
 | 
| index 9c9362b2f003d5e648b8186813d8fe85da300b70..7054ea7e4c40664b01ad89c0cb4c90f029cf6ed5 100644
 | 
| --- a/src/flag-definitions.h
 | 
| +++ b/src/flag-definitions.h
 | 
| @@ -190,6 +190,9 @@ DEFINE_bool(clever_optimizations,
 | 
|              true,
 | 
|              "Optimize object size, Array shift, DOM strings and string +")
 | 
|  DEFINE_bool(pretenure_literals, true, "allocate literals in old space")
 | 
| +DEFINE_bool(track_fields, false, "track fields with only smi values")
 | 
| +DEFINE_bool(track_double_fields, false, "track fields with double values")
 | 
| +DEFINE_implication(track_double_fields, track_fields)
 | 
|  
 | 
|  // Flags for data representation optimizations
 | 
|  DEFINE_bool(unbox_double_arrays, true, "automatically unbox arrays of doubles")
 | 
| 
 |