[proxies] Make Object.{freeze,seal} behave correctly for proxies.

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 1846 matching lines @@
       PropertyDescriptor* desc, PropertyDescriptor* current,
       ShouldThrow should_throw, Handle<Name> property_name = Handle<Name>());
 
   static bool GetOwnPropertyDescriptor(Isolate* isolate,
                                        Handle<JSReceiver> object,
                                        Handle<Object> key,
                                        PropertyDescriptor* desc);
   static bool GetOwnPropertyDescriptor(LookupIterator* it,
                                        PropertyDescriptor* desc);
 
-  // Disallow further properties to be added to the object.  This is
-  // ES6's [[PreventExtensions]] when passed DONT_THROW.
+  typedef PropertyAttributes IntegrityLevel;
+
+  // ES6 7.3.14 (when passed DONT_THROW)
+  // 'level' must be SEALED or FROZEN.
+  MUST_USE_RESULT static Maybe<bool> SetIntegrityLevel(
+      Handle<JSReceiver> object, IntegrityLevel lvl, ShouldThrow should_throw);
+
+  // ES6 [[PreventExtensions]] (when passed DONT_THROW)
   MUST_USE_RESULT static Maybe<bool> PreventExtensions(
       Handle<JSReceiver> object, ShouldThrow should_throw);
 
   MUST_USE_RESULT static Maybe<bool> IsExtensible(Handle<JSReceiver> object);
 
   // Tests for the fast common case for property enumeration.
   bool IsSimpleEnum();
 
   // Returns the class name ([[Class]] property in the specification).
   String* class_name();
@@ skipping 33 matching lines @@
   // be returned in case no hash was created yet.
   inline Object* GetIdentityHash();
 
   // Retrieves a permanent object identity hash code. May create and store a
   // hash code if needed and none exists.
   inline static Handle<Smi> GetOrCreateIdentityHash(
       Handle<JSReceiver> object);
 
   enum KeyCollectionType { OWN_ONLY, INCLUDE_PROTOS };
 
+  // ES6 [[OwnPropertyKeys]] (modulo return type)
+  MUST_USE_RESULT static MaybeHandle<FixedArray> OwnPropertyKeys(
+      Handle<JSReceiver> object) {
+    return GetKeys(object, JSReceiver::OWN_ONLY, ALL_PROPERTIES,
+                   CONVERT_TO_STRING);
+  }
+
   // Computes the enumerable keys for a JSObject. Used for implementing
   // "for (n in object) { }".
   MUST_USE_RESULT static MaybeHandle<FixedArray> GetKeys(
       Handle<JSReceiver> object, KeyCollectionType type, PropertyFilter filter,
       GetKeysConversion keys_conversion = KEEP_NUMBERS);
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(JSReceiver);
 };
 
@@ skipping 418 matching lines @@
                              Object* pre_allocated_value, Object* filler_value);
 
   // Check whether this object references another object
   bool ReferencesObject(Object* obj);
 
   MUST_USE_RESULT static Maybe<bool> PreventExtensions(
       Handle<JSObject> object, ShouldThrow should_throw);
 
   static bool IsExtensible(Handle<JSObject> object);
 
-  // ES5 Object.seal
-  MUST_USE_RESULT static MaybeHandle<Object> Seal(Handle<JSObject> object);
-
-  // ES5 Object.freeze
-  MUST_USE_RESULT static MaybeHandle<Object> Freeze(Handle<JSObject> object);
-
   // Called the first time an object is observed with ES7 Object.observe.
   static void SetObserved(Handle<JSObject> object);
 
   // Copy object.
   enum DeepCopyHints { kNoHints = 0, kObjectIsShallow = 1 };
 
   MUST_USE_RESULT static MaybeHandle<JSObject> DeepCopy(
       Handle<JSObject> object,
       AllocationSiteUsageContext* site_context,
       DeepCopyHints hints = kNoHints);
@@ skipping 8309 matching lines @@
     }
     return value;
   }
 };
 
 
 }  // NOLINT, false-positive due to second-order macros.
 }  // NOLINT, false-positive due to second-order macros.
 
 #endif  // V8_OBJECTS_H_