[heap] Prevent direct access to StoreBuffer.

src/heap/heap.h

Index: src/heap/heap.h
diff --git a/src/heap/heap.h b/src/heap/heap.h
index 540185731cc4eb02d3c8d21ddb47f870253a8500..fd74ff2f498f40d151399fa71cfd16d7af3ba1fd 100644
--- a/src/heap/heap.h
+++ b/src/heap/heap.h
@@ -994,10 +994,6 @@ class Heap {
     roots_[kEmptyScriptRootIndex] = script;
   }
 
-  void public_set_store_buffer_top(Address* top) {
-    roots_[kStoreBufferTopRootIndex] = reinterpret_cast<Smi*>(top);
-  }
-
   void public_set_materialized_objects(FixedArray* objects) {
     roots_[kMaterializedObjectsRootIndex] = objects;
   }
@@ -1005,10 +1001,6 @@ class Heap {
   // Generated code can embed this address to get access to the roots.
   Object** roots_array_start() { return roots_; }
 
-  Address* store_buffer_top_address() {
-    return reinterpret_cast<Address*>(&roots_[kStoreBufferTopRootIndex]);
-  }
-
   void CheckHandleCount();
 
   // Number of "runtime allocations" done so far.
@@ -1029,12 +1021,6 @@ class Heap {
     return index < OBJECT_STATS_COUNT ? object_sizes_last_time_[index] : 0;
   }
 
-  // Write barrier support for address[offset] = o.
-  INLINE(void RecordWrite(Address address, int offset));
-
-  // Write barrier support for address[start : start + len[ = o.
-  INLINE(void RecordWrites(Address address, int start, int len));
-
   inline HeapState gc_state() { return gc_state_; }
 
   inline bool IsInGCPostProcessing() { return gc_post_processing_depth_ > 0; }
@@ -1094,10 +1080,6 @@ class Heap {
 
   void IncrementDeferredCount(v8::Isolate::UseCounterFeature feature);
 
-  ExternalStringTable* external_string_table() {
-    return &external_string_table_;
-  }
-
   bool concurrent_sweeping_enabled() { return concurrent_sweeping_enabled_; }
 
   inline bool OldGenerationAllocationLimitReached();
@@ -1307,7 +1289,9 @@ class Heap {
     return &mark_compact_collector_;
   }
 
-  StoreBuffer* store_buffer() { return &store_buffer_; }
+  ExternalStringTable* external_string_table() {
+    return &external_string_table_;
+  }
 
   // ===========================================================================
   // Inline allocation. ========================================================
@@ -1365,6 +1349,20 @@ class Heap {
                                          ObjectSlotCallback callback);
 
   // ===========================================================================
+  // Store buffer API. =========================================================
+  // ===========================================================================
+
+  // Write barrier support for address[offset] = o.
+  INLINE(void RecordWrite(Address address, int offset));
+
+  // Write barrier support for address[start : start + len[ = o.
+  INLINE(void RecordWrites(Address address, int start, int len));
+
+  Address* store_buffer_top_address() {
+    return reinterpret_cast<Address*>(&roots_[kStoreBufferTopRootIndex]);
+  }
+
+  // ===========================================================================
   // Incremental marking API. ==================================================
   // ===========================================================================
 
@@ -1683,6 +1681,8 @@ class Heap {
   ROOT_LIST(ROOT_ACCESSOR)
 #undef ROOT_ACCESSOR
 
+  StoreBuffer* store_buffer() { return &store_buffer_; }
+
   void set_current_gc_flags(int flags) {
     current_gc_flags_ = flags;
     DCHECK(!ShouldFinalizeIncrementalMarking() ||
@@ -2411,6 +2411,7 @@ class Heap {
   friend class MarkCompactMarkingVisitor;
   friend class MapCompact;
   friend class Page;
+  friend class StoreBuffer;
 
   // Used in cctest.
   friend class HeapTester;