All private symbols are own symbols

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 8550 matching lines @@
   // Returns a hash value used for the property table
   inline uint32_t Hash();
 
   // Equality operations.
   inline bool Equals(Name* other);
   inline static bool Equals(Handle<Name> one, Handle<Name> two);
 
   // Conversion.
   inline bool AsArrayIndex(uint32_t* index);
 
-  // Whether name can only name own properties.
-  inline bool IsOwn();
+  // If the name is private, it can only name own properties.
+  inline bool IsPrivate();
 
   DECLARE_CAST(Name)
 
   DECLARE_PRINTER(Name)
 #if TRACE_MAPS
   void NameShortPrint();
   int NameShortPrint(Vector<char> str);
 #endif
 
   // Layout description.
@@ skipping 57 matching lines @@
   static inline bool IsHashFieldComputed(uint32_t field);
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(Name);
 };
 
 
 // ES6 symbols.
 class Symbol: public Name {
  public:
-  // [name]: the print name of a symbol, or undefined if none.
+  // [name]: The print name of a symbol, or undefined if none.
   DECL_ACCESSORS(name, Object)
 
   DECL_ACCESSORS(flags, Smi)
 
-  // [is_private]: whether this is a private symbol.
+  // [is_private]: Whether this is a private symbol.  Private symbols can only
+  // be used to designate own properties of objects.
   DECL_BOOLEAN_ACCESSORS(is_private)
 
-  // [is_own]: whether this is an own symbol, that is, only used to designate
-  // own properties of objects.
-  DECL_BOOLEAN_ACCESSORS(is_own)
-
   DECLARE_CAST(Symbol)
 
   // Dispatched behavior.
   DECLARE_PRINTER(Symbol)
   DECLARE_VERIFIER(Symbol)
 
   // Layout description.
   static const int kNameOffset = Name::kSize;
   static const int kFlagsOffset = kNameOffset + kPointerSize;
   static const int kSize = kFlagsOffset + kPointerSize;
 
   typedef FixedBodyDescriptor<kNameOffset, kFlagsOffset, kSize> BodyDescriptor;
 
   void SymbolShortPrint(std::ostream& os);
 
  private:
   static const int kPrivateBit = 0;
-  static const int kOwnBit = 1;
 
   const char* PrivateSymbolToName() const;
 
 #if TRACE_MAPS
   friend class Name;  // For PrivateSymbolToName.
 #endif
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(Symbol);
 };
 
@@ skipping 2160 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_