Revert of Replace slots buffer with remembered set.

src/heap/objects-visiting-inl.h

Index: src/heap/objects-visiting-inl.h
diff --git a/src/heap/objects-visiting-inl.h b/src/heap/objects-visiting-inl.h
index c415713ee3f1c04ebc4713292d4289369f0a5624..d71c879a739ec93eba1f5443b97f463f3064514d 100644
--- a/src/heap/objects-visiting-inl.h
+++ b/src/heap/objects-visiting-inl.h
@@ -220,12 +220,11 @@
     Heap* heap, RelocInfo* rinfo) {
   DCHECK(rinfo->rmode() == RelocInfo::EMBEDDED_OBJECT);
   HeapObject* object = HeapObject::cast(rinfo->target_object());
-  Code* host = rinfo->host();
-  heap->mark_compact_collector()->RecordRelocSlot(host, rinfo, object);
+  heap->mark_compact_collector()->RecordRelocSlot(rinfo, object);
   // TODO(ulan): It could be better to record slots only for strongly embedded
   // objects here and record slots for weakly embedded object during clearing
   // of non-live references in mark-compact.
-  if (!host->IsWeakObject(object)) {
+  if (!rinfo->host()->IsWeakObject(object)) {
     StaticVisitor::MarkObject(heap, object);
   }
 }
@@ -236,9 +235,8 @@
                                                     RelocInfo* rinfo) {
   DCHECK(rinfo->rmode() == RelocInfo::CELL);
   Cell* cell = rinfo->target_cell();
-  Code* host = rinfo->host();
-  heap->mark_compact_collector()->RecordRelocSlot(host, rinfo, cell);
-  if (!host->IsWeakObject(cell)) {
+  heap->mark_compact_collector()->RecordRelocSlot(rinfo, cell);
+  if (!rinfo->host()->IsWeakObject(cell)) {
     StaticVisitor::MarkObject(heap, cell);
   }
 }
@@ -250,8 +248,7 @@
   DCHECK(RelocInfo::IsDebugBreakSlot(rinfo->rmode()) &&
          rinfo->IsPatchedDebugBreakSlotSequence());
   Code* target = Code::GetCodeFromTargetAddress(rinfo->debug_call_address());
-  Code* host = rinfo->host();
-  heap->mark_compact_collector()->RecordRelocSlot(host, rinfo, target);
+  heap->mark_compact_collector()->RecordRelocSlot(rinfo, target);
   StaticVisitor::MarkObject(heap, target);
 }
 
@@ -271,8 +268,7 @@
                      rinfo->host()->constant_pool());
     target = Code::GetCodeFromTargetAddress(rinfo->target_address());
   }
-  Code* host = rinfo->host();
-  heap->mark_compact_collector()->RecordRelocSlot(host, rinfo, target);
+  heap->mark_compact_collector()->RecordRelocSlot(rinfo, target);
   StaticVisitor::MarkObject(heap, target);
 }
 
@@ -283,8 +279,7 @@
   DCHECK(RelocInfo::IsCodeAgeSequence(rinfo->rmode()));
   Code* target = rinfo->code_age_stub();
   DCHECK(target != NULL);
-  Code* host = rinfo->host();
-  heap->mark_compact_collector()->RecordRelocSlot(host, rinfo, target);
+  heap->mark_compact_collector()->RecordRelocSlot(rinfo, target);
   StaticVisitor::MarkObject(heap, target);
 }