[API] remove (deprecated) hidden properties.

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index ca5f709813e32064d76dc29092f5e73057fea6e2..f87163f95a092acdbad2ea15379b37ab2334ecda 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -2207,30 +2207,6 @@ class JSObject: public JSReceiver {
   MUST_USE_RESULT static MaybeHandle<Object> GetPropertyWithInterceptor(
       LookupIterator* it, bool* done);
 
-  // Accessors for hidden properties object.
-  //
-  // Hidden properties are not own properties of the object itself.  Instead
-  // they are stored in an auxiliary structure kept as an own property with a
-  // special name Heap::hidden_properties_symbol(). But if the receiver is a
-  // JSGlobalProxy then the auxiliary object is a property of its prototype, and
-  // if it's a detached proxy, then you can't have hidden properties.
-
-  // Sets a hidden property on this object. Returns this object if successful,
-  // undefined if called on a detached proxy.
-  static Handle<Object> SetHiddenProperty(Handle<JSObject> object,
-                                          Handle<Name> key,
-                                          Handle<Object> value);
-  // Gets the value of a hidden property with the given key. Returns the hole
-  // if the property doesn't exist (or if called on a detached proxy),
-  // otherwise returns the value set for the key.
-  Object* GetHiddenProperty(Handle<Name> key);
-  // Deletes a hidden property. Deleting a non-existing property is
-  // considered successful.
-  static void DeleteHiddenProperty(Handle<JSObject> object,
-                                   Handle<Name> key);
-  // Returns true if the object has a property with the hidden string as name.
-  static bool HasHiddenProperties(Handle<JSObject> object);
-
   static void ValidateElements(Handle<JSObject> object);
 
   // Makes sure that this object can contain HeapObject as elements.
@@ -2515,21 +2491,6 @@ class JSObject: public JSReceiver {
                                     ElementsKind kind,
                                     Object* object);
 
-  // Return the hash table backing store or the inline stored identity hash,
-  // whatever is found.
-  MUST_USE_RESULT Object* GetHiddenPropertiesHashTable();
-
-  // Return the hash table backing store for hidden properties.  If there is no
-  // backing store, allocate one.
-  static Handle<ObjectHashTable> GetOrCreateHiddenPropertiesHashtable(
-      Handle<JSObject> object);
-
-  // Set the hidden property backing store to either a hash table or
-  // the inline-stored identity hash.
-  static Handle<Object> SetHiddenPropertiesHashTable(
-      Handle<JSObject> object,
-      Handle<Object> value);
-
   static Handle<Object> GetIdentityHash(Isolate* isolate,
                                         Handle<JSObject> object);