[proxies] use [[GetPrototypeOf]] trap in for-in

src/keys.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_KEY_ACCUMULATOR_H_
 #define V8_KEY_ACCUMULATOR_H_
 
 #include "src/isolate.h"
 #include "src/objects.h"
 
@@ skipping 34 matching lines @@
   Maybe<bool> AddKeysFromProxy(Handle<JSProxy> proxy, Handle<FixedArray> keys);
   void AddElementKeysFromInterceptor(Handle<JSObject> array);
   // Jump to the next level, pushing the current |levelLength_| to
   // |levelLengths_| and adding a new list to |elements_|.
   void NextPrototype();
   // Sort the integer indices in the last list in |elements_|
   void SortCurrentElementsList();
   Handle<FixedArray> GetKeys(GetKeysConversion convert = KEEP_NUMBERS);
   int length() { return length_; }
   Isolate* isolate() { return isolate_; }
+  void set_filter_proxy_keys(bool filter) { filter_proxy_keys_ = filter; }
 
  private:
   bool AddIntegerKey(uint32_t key);
   bool AddStringKey(Handle<Object> key, AddKeyConversion convert);
   bool AddSymbolKey(Handle<Object> array);
   void SortCurrentElementsListRemoveDuplicates();
 
   Isolate* isolate_;
   KeyCollectionType type_;
   PropertyFilter filter_;
+  bool filter_proxy_keys_ = true;
   // |elements_| contains the sorted element keys (indices) per level.
   std::vector<std::vector<uint32_t>*> elements_;
   // |protoLengths_| contains the total number of keys (elements + properties)
   // per level. Negative values mark counts for a level with keys from a proxy.
   std::vector<int> level_lengths_;
   // |string_properties_| contains the unique String property keys for all
   // levels in insertion order per level.
   Handle<OrderedHashSet> string_properties_;
   // |symbol_properties_| contains the unique Symbol property keys for all
   // levels in insertion order per level.
@@ skipping 19 matching lines @@
   FastKeyAccumulator(Isolate* isolate, Handle<JSReceiver> receiver,
                      KeyCollectionType type, PropertyFilter filter)
       : isolate_(isolate), receiver_(receiver), type_(type), filter_(filter) {
     Prepare();
     // TODO(cbruni): pass filter_ directly to the KeyAccumulator.
     USE(filter_);
   }
 
   bool is_receiver_simple_enum() { return is_receiver_simple_enum_; }
   bool has_empty_prototype() { return has_empty_prototype_; }
+  void set_filter_proxy_keys(bool filter) { filter_proxy_keys_ = filter; }
 
   MaybeHandle<FixedArray> GetKeys(GetKeysConversion convert = KEEP_NUMBERS);
 
  private:
   void Prepare();
   MaybeHandle<FixedArray> GetKeysFast(GetKeysConversion convert);
   MaybeHandle<FixedArray> GetKeysSlow(GetKeysConversion convert);
 
   Isolate* isolate_;
   Handle<JSReceiver> receiver_;
   KeyCollectionType type_;
   PropertyFilter filter_;
   bool is_receiver_simple_enum_ = false;
   bool has_empty_prototype_ = false;
+  bool filter_proxy_keys_ = true;
 
   DISALLOW_COPY_AND_ASSIGN(FastKeyAccumulator);
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_KEY_ACCUMULATOR_H_