[heap] Prevent direct access to StoreBuffer.

src/heap/store-buffer-inl.h

Index: src/heap/store-buffer-inl.h
diff --git a/src/heap/store-buffer-inl.h b/src/heap/store-buffer-inl.h
index 90f54766d2ba1bae3434f3ce6dbfc866548356b7..230384af7a34f74ce42281308512b74af0df68e7 100644
--- a/src/heap/store-buffer-inl.h
+++ b/src/heap/store-buffer-inl.h
@@ -12,16 +12,11 @@
 namespace v8 {
 namespace internal {
 
-Address StoreBuffer::TopAddress() {
-  return reinterpret_cast<Address>(heap_->store_buffer_top_address());
-}
-
-
 void StoreBuffer::Mark(Address addr) {
   DCHECK(!heap_->code_space()->Contains(addr));
   Address* top = reinterpret_cast<Address*>(heap_->store_buffer_top());
   *top++ = addr;
-  heap_->public_set_store_buffer_top(top);
+  heap_->set_store_buffer_top(reinterpret_cast<Smi*>(top));
   if ((reinterpret_cast<uintptr_t>(top) & kStoreBufferOverflowBit) != 0) {
     DCHECK(top == limit_);
     Compact();