Revert of Replace slots buffer with remembered set.

src/heap/heap.cc

 // 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.
 
 #include "src/heap/heap.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/ast/scopeinfo.h"
 #include "src/base/bits.h"
@@ skipping 5556 matching lines @@
   isolate_->handle_scope_implementer()->Iterate(&v);
 }
 
 void Heap::ClearRecordedSlot(HeapObject* object, Object** slot) {
   if (!InNewSpace(object)) {
     store_buffer()->MoveEntriesToRememberedSet();
     Address slot_addr = reinterpret_cast<Address>(slot);
     Page* page = Page::FromAddress(slot_addr);
     DCHECK_EQ(page->owner()->identity(), OLD_SPACE);
     RememberedSet<OLD_TO_NEW>::Remove(page, slot_addr);
-    RememberedSet<OLD_TO_OLD>::Remove(page, slot_addr);
   }
 }
 
 void Heap::ClearRecordedSlotRange(HeapObject* object, Object** start,
                                   Object** end) {
   if (!InNewSpace(object)) {
     store_buffer()->MoveEntriesToRememberedSet();
     Address start_addr = reinterpret_cast<Address>(start);
     Address end_addr = reinterpret_cast<Address>(end);
     Page* page = Page::FromAddress(start_addr);
     DCHECK_EQ(page->owner()->identity(), OLD_SPACE);
     RememberedSet<OLD_TO_NEW>::RemoveRange(page, start_addr, end_addr);
-    RememberedSet<OLD_TO_OLD>::RemoveRange(page, start_addr, end_addr);
   }
 }
 
 Space* AllSpaces::next() {
   switch (counter_++) {
     case NEW_SPACE:
       return heap_->new_space();
     case OLD_SPACE:
       return heap_->old_space();
     case CODE_SPACE:
@@ skipping 722 matching lines @@
 }
 
 
 // static
 int Heap::GetStaticVisitorIdForMap(Map* map) {
   return StaticVisitorBase::GetVisitorId(map);
 }
 
 }  // namespace internal
 }  // namespace v8