Object.observe: avoid accessing acceptList properties more than once

src/runtime.cc

 // 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.
 
 #include <stdlib.h>
 #include <limits>
 
 #include "v8.h"
 
 #include "accessors.h"
@@ skipping 14981 matching lines @@
       ContextsHaveSameOrigin(creation_context, isolate->native_context()));
 }
 
 
 RUNTIME_FUNCTION(Runtime_ObjectObserveInObjectContext) {
   HandleScope scope(isolate);
   ASSERT(args.length() == 3);
   CONVERT_ARG_HANDLE_CHECKED(JSObject, object, 0);
   CONVERT_ARG_HANDLE_CHECKED(JSFunction, callback, 1);
   CONVERT_ARG_HANDLE_CHECKED(Object, accept, 2);
-  RUNTIME_ASSERT(accept->IsUndefined() || accept->IsJSObject());
 
   Handle<Context> context(object->GetCreationContext(), isolate);
   Handle<JSFunction> function(context->native_object_observe(), isolate);
   Handle<Object> call_args[] = { object, callback, accept };
   Handle<Object> result;
 
   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
       isolate, result,
       Execution::Call(isolate, function,
           handle(context->object_function(), isolate),
@@ skipping 250 matching lines @@
   }
   return NULL;
 }
 
 
 const Runtime::Function* Runtime::FunctionForId(Runtime::FunctionId id) {
   return &(kIntrinsicFunctions[static_cast<int>(id)]);
 }
 
 } }  // namespace v8::internal