[heap] Make SlotSet allocation thread-safe and refactor code.

src/heap/spaces-inl.h

Index: src/heap/spaces-inl.h
diff --git a/src/heap/spaces-inl.h b/src/heap/spaces-inl.h
index 167e5fb70facf7e786b49cf1db01fbb30f7793c4..bf1c75cea8ce7e9fa11f56f0c681b882d965ce30 100644
--- a/src/heap/spaces-inl.h
+++ b/src/heap/spaces-inl.h
@@ -326,16 +326,16 @@ void Page::MarkNeverAllocateForTesting() {
 
 void Page::MarkEvacuationCandidate() {
   DCHECK(!IsFlagSet(NEVER_EVACUATE));
-  DCHECK_NULL(old_to_old_slots_);
-  DCHECK_NULL(typed_old_to_old_slots_);
+  DCHECK_NULL(slot_set_[OLD_TO_OLD].Value());

[ulan, 2017/03/20 14:27:15]

DCHECK_NULL(slot_set<OLD_TO_OLD>()) here and below.

[Hannes Payer (out of office), 2017/03/20 15:07:08]

Done.

+  DCHECK_NULL(typed_slot_set_[OLD_TO_OLD].Value());
   SetFlag(EVACUATION_CANDIDATE);
   reinterpret_cast<PagedSpace*>(owner())->free_list()->EvictFreeListItems(this);
 }
 
 void Page::ClearEvacuationCandidate() {
   if (!IsFlagSet(COMPACTION_WAS_ABORTED)) {
-    DCHECK_NULL(old_to_old_slots_);
-    DCHECK_NULL(typed_old_to_old_slots_);
+    DCHECK_NULL(slot_set_[OLD_TO_OLD].Value());
+    DCHECK_NULL(typed_slot_set_[OLD_TO_OLD].Value());
   }
   ClearFlag(EVACUATION_CANDIDATE);
   InitializeFreeListCategories();