Revert of Fix old space check in IsSlotInBlackObject.

src/heap/mark-compact.cc

Index: src/heap/mark-compact.cc
diff --git a/src/heap/mark-compact.cc b/src/heap/mark-compact.cc
index 51e3f1e7eb639766829694922f314c09f990f0dc..0c9eeff0041d3c92988d407e162bb50d81718468 100644
--- a/src/heap/mark-compact.cc
+++ b/src/heap/mark-compact.cc
@@ -3059,8 +3059,7 @@
 
 bool MarkCompactCollector::IsSlotInBlackObject(Page* p, Address slot) {
   // This function does not support large objects right now.
-  Space* owner = p->owner();
-  if (owner == heap_->lo_space() || owner == NULL) return true;
+  if (p->owner() == NULL) return true;
 
   uint32_t mark_bit_index = p->AddressToMarkbitIndex(slot);
   unsigned int start_index = mark_bit_index >> Bitmap::kBitsPerCellLog2;