| Index: src/flag-definitions.h | 
| diff --git a/src/flag-definitions.h b/src/flag-definitions.h | 
| index 6951d8c8b5dcc51201829d0f5a25a502e3a77c22..56459fd3d3660b5f3b7d1b1b4dd7025e6068369d 100644 | 
| --- a/src/flag-definitions.h | 
| +++ b/src/flag-definitions.h | 
| @@ -930,6 +930,11 @@ DEFINE_INT(dump_allocations_digest_at_alloc, 0, | 
| DEFINE_BOOL(enable_ool_constant_pool, V8_OOL_CONSTANT_POOL, | 
| "enable use of out-of-line constant pools (ARM only)") | 
|  | 
| +DEFINE_BOOL(unbox_double_fields, V8_DOUBLE_FIELDS_UNBOXING, | 
| +            "enable in-object double fields unboxing (64-bit only)") | 
| +DEFINE_IMPLICATION(unbox_double_fields, track_double_fields) | 
| + | 
| + | 
| // Cleanup... | 
| #undef FLAG_FULL | 
| #undef FLAG_READONLY | 
|  |