[FeedbackVector] Clarify the way the feedback vector is installed.

src/flag-definitions.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This file defines all of the flags.  It is separated into different section,
 // for Debug, Release, Logging and Profiling, etc.  To add a new flag, find the
 // correct section, and use one of the DEFINE_ macros, without a trailing ';'.
 //
 // This include does not have a guard, because it is a template-style include,
 // which can be included multiple times in different modes.  It expects to have
@@ skipping 273 matching lines @@
 DEFINE_BOOL(track_heap_object_fields, true, "track fields with heap values")
 DEFINE_BOOL(track_computed_fields, true, "track computed boilerplate fields")
 DEFINE_IMPLICATION(track_double_fields, track_fields)
 DEFINE_IMPLICATION(track_heap_object_fields, track_fields)
 DEFINE_IMPLICATION(track_computed_fields, track_fields)
 DEFINE_BOOL(track_field_types, true, "track field types")
 DEFINE_IMPLICATION(track_field_types, track_fields)
 DEFINE_IMPLICATION(track_field_types, track_heap_object_fields)
 DEFINE_BOOL(type_profile, false, "collect type information")
 
-// Flags for strongly rooting literal arrays in the feedback vector.
-DEFINE_BOOL(trace_strong_rooted_literals, false, "trace literal rooting")
-
 // Flags for optimization types.
 DEFINE_BOOL(optimize_for_size, false,
             "Enables optimizations which favor memory size over execution "
             "speed")
 
 DEFINE_VALUE_IMPLICATION(optimize_for_size, max_semi_space_size, 1)
 
 // Flags for data representation optimizations
 DEFINE_BOOL(unbox_double_arrays, true, "automatically unbox arrays of doubles")
 DEFINE_BOOL(string_slices, true, "use string slices")
@@ skipping 1004 matching lines @@
 #undef DEFINE_ALIAS_FLOAT
 #undef DEFINE_ALIAS_ARGS
 
 #undef FLAG_MODE_DECLARE
 #undef FLAG_MODE_DEFINE
 #undef FLAG_MODE_DEFINE_DEFAULTS
 #undef FLAG_MODE_META
 #undef FLAG_MODE_DEFINE_IMPLICATIONS
 
 #undef COMMA