Reland "Merge cellspace into old pointer space"

src/heap/spaces.h

Index: src/heap/spaces.h
diff --git a/src/heap/spaces.h b/src/heap/spaces.h
index cd5e9f2c7be4d8b44a6c6e921fd6f76e0aaee442..b635f4f2efcace5b4493c9527b7f263d36619b8f 100644
--- a/src/heap/spaces.h
+++ b/src/heap/spaces.h
@@ -2658,31 +2658,6 @@ class MapSpace : public PagedSpace {
 
 
 // -----------------------------------------------------------------------------
-// Old space for simple property cell objects
-
-class CellSpace : public PagedSpace {
- public:
-  // Creates a property cell space object with a maximum capacity.
-  CellSpace(Heap* heap, intptr_t max_capacity, AllocationSpace id)
-      : PagedSpace(heap, max_capacity, id, NOT_EXECUTABLE) {}
-
-  virtual int RoundSizeDownToObjectAlignment(int size) {
-    if (base::bits::IsPowerOfTwo32(Cell::kSize)) {
-      return RoundDown(size, Cell::kSize);
-    } else {
-      return (size / Cell::kSize) * Cell::kSize;
-    }
-  }
-
- protected:
-  virtual void VerifyObject(HeapObject* obj);
-
- public:
-  TRACK_MEMORY("CellSpace")
-};
-
-
-// -----------------------------------------------------------------------------
 // Large objects ( > Page::kMaxHeapObjectSize ) are allocated and managed by
 // the large object space. A large object is allocated from OS heap with
 // extra padding bytes (Page::kPageSize + Page::kObjectStartOffset).