[cleanup] Drop FLAG_eliminate_prototype_chain_checks

src/objects.cc

 // Copyright 2015 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.
 
 #include "src/objects.h"
 
 #include <cmath>
 #include <iomanip>
 #include <sstream>
 
@@ skipping 2779 matching lines @@
   }
   // Otherwise, properties will need to be moved to the backing store.
   return true;
 }
 
 
 // static
 void JSObject::UpdatePrototypeUserRegistration(Handle<Map> old_map,
                                                Handle<Map> new_map,
                                                Isolate* isolate) {
-  if (!FLAG_track_prototype_users) return;
   if (!old_map->is_prototype_map()) return;
   DCHECK(new_map->is_prototype_map());
   bool was_registered = JSObject::UnregisterPrototypeUser(old_map, isolate);
   new_map->set_prototype_info(old_map->prototype_info());
   old_map->set_prototype_info(Smi::FromInt(0));
   if (FLAG_trace_prototype_users) {
     PrintF("Moving prototype_info %p from map %p to map %p.\n",
            reinterpret_cast<void*>(new_map->prototype_info()),
            reinterpret_cast<void*>(*old_map),
            reinterpret_cast<void*>(*new_map));
@@ skipping 8780 matching lines @@
 
 // static
 void JSObject::ReoptimizeIfPrototype(Handle<JSObject> object) {
   if (!object->map()->is_prototype_map()) return;
   OptimizeAsPrototype(object, FAST_PROTOTYPE);
 }
 
 
 // static
 void JSObject::LazyRegisterPrototypeUser(Handle<Map> user, Isolate* isolate) {
-  DCHECK(FLAG_track_prototype_users);
   // Contract: In line with InvalidatePrototypeChains()'s requirements,
   // leaf maps don't need to register as users, only prototypes do.
   DCHECK(user->is_prototype_map());
 
   Handle<Map> current_user = user;
   Handle<PrototypeInfo> current_user_info =
       Map::GetOrCreatePrototypeInfo(user, isolate);
   for (PrototypeIterator iter(user); !iter.IsAtEnd(); iter.Advance()) {
     // Walk up the prototype chain as far as links haven't been registered yet.
     if (current_user_info->registry_slot() != PrototypeInfo::UNREGISTERED) {
@@ skipping 85 matching lines @@
   Map* user;
   while ((user = iterator.Next<Map>())) {
     // Walk the prototype chain (backwards, towards leaf objects) if necessary.
     InvalidatePrototypeChainsInternal(user);
   }
 }
 
 
 // static
 void JSObject::InvalidatePrototypeChains(Map* map) {
-  if (!FLAG_eliminate_prototype_chain_checks) return;
   DisallowHeapAllocation no_gc;
   InvalidatePrototypeChainsInternal(map);
 }
 
 
 // static
 Handle<PrototypeInfo> Map::GetOrCreatePrototypeInfo(Handle<JSObject> prototype,
                                                     Isolate* isolate) {
   Object* maybe_proto_info = prototype->map()->prototype_info();
   if (maybe_proto_info->IsPrototypeInfo()) {
@@ skipping 6675 matching lines @@
   if (cell->value() != *new_value) {
     cell->set_value(*new_value);
     Isolate* isolate = cell->GetIsolate();
     cell->dependent_code()->DeoptimizeDependentCodeGroup(
         isolate, DependentCode::kPropertyCellChangedGroup);
   }
 }
 
 }  // namespace internal
 }  // namespace v8