Disallow Object.observe calls on access-checked objects

src/runtime/runtime-object.cc

 // Copyright 2014 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.
 
 #include "src/runtime/runtime-utils.h"
 
 #include "src/arguments.h"
 #include "src/bootstrapper.h"
 #include "src/debug/debug.h"
 #include "src/isolate-inl.h"
@@ skipping 1533 matching lines @@
 
 // ES6 section 7.4.7 CreateIterResultObject ( value, done )
 RUNTIME_FUNCTION(Runtime_CreateIterResultObject) {
   HandleScope scope(isolate);
   DCHECK_EQ(2, args.length());
   CONVERT_ARG_HANDLE_CHECKED(Object, value, 0);
   CONVERT_ARG_HANDLE_CHECKED(Object, done, 1);
   return *isolate->factory()->NewJSIteratorResult(value, done);
 }
 
+
+RUNTIME_FUNCTION(Runtime_IsAccessCheckNeeded) {
+  SealHandleScope shs(isolate);
+  DCHECK_EQ(1, args.length());
+  CONVERT_ARG_CHECKED(Object, object, 0);
+  return isolate->heap()->ToBoolean(object->IsAccessCheckNeeded());
+}
+
+
 }  // namespace internal
 }  // namespace v8