[objects] do not visit ArrayBuffer's backing store

src/objects.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_OBJECTS_H_
 #define V8_OBJECTS_H_
 
 #include <iosfwd>
 
 #include "src/allocation.h"
@@ skipping 9658 matching lines @@
 #if V8_TARGET_LITTLE_ENDIAN || !V8_HOST_ARCH_64_BIT
   static const int kBitFieldOffset = kBitFieldSlot;
 #else
   static const int kBitFieldOffset = kBitFieldSlot + kIntSize;
 #endif
   static const int kSize = kBitFieldSlot + kPointerSize;
 
   static const int kSizeWithInternalFields =
       kSize + v8::ArrayBuffer::kInternalFieldCount * kPointerSize;
 
+  class BodyDescriptor {

[jochen (gone - plz use gerrit), 2015/09/14 10:04:36]

instead of having a body description, just add two methods called
JSArrayBufferIterateBody() to JSArrayBuffer (similar to what FixedTypedArrayBase
has)

[fedor.indutny, 2015/09/14 17:08:16]

Acknowledged.

+   public:
+    static const int kStartOffset = JSObject::BodyDescriptor::kStartOffset;
+    static const int kEndOffset = kSizeWithInternalFields - kPointerSize;
+    static const int kSize = kSizeWithInternalFields;
+
+    template <typename StaticVisitor>
+    static inline void IterateBody(Heap* heap, HeapObject* obj);
+
+    static inline void IterateBody(HeapObject* obj, ObjectVisitor* v);
+  };
+
   class IsExternal : public BitField<bool, 1, 1> {};
   class IsNeuterable : public BitField<bool, 2, 1> {};
   class WasNeutered : public BitField<bool, 3, 1> {};
   class IsShared : public BitField<bool, 4, 1> {};
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(JSArrayBuffer);
 };
 
 
@@ skipping 777 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_