[runtime] [proxy] Fix Object.prototype.PropertyIsEnumerable to support

proxies.

BUG=v8:1543
LOG=N

Review URL: https://codereview.chromium.org/1484313003

Cr-Commit-Position: refs/heads/master@{#32473}

src/js/v8natives.js

@@ -207,16 +207,9 @@ function ObjectIsPrototypeOf(V) {
 }
 
 
-// ECMA-262 - 15.2.4.6
+// ES6 19.1.3.4
 function ObjectPropertyIsEnumerable(V) {
   var P = TO_NAME(V);
-  if (%_IsJSProxy(this)) {
-    // TODO(rossberg): adjust once there is a story for symbols vs proxies.
-    if (IS_SYMBOL(V)) return false;
-
-    var desc = GetOwnPropertyJS(this, P);
-    return IS_UNDEFINED(desc) ? false : desc.isEnumerable();
-  }
   return %IsPropertyEnumerable(TO_OBJECT(this), P);
 }
 

src/runtime/runtime-object.cc

@@ -755,13 +755,13 @@ RUNTIME_FUNCTION(Runtime_IsPropertyEnumerable) {
   HandleScope scope(isolate);
   DCHECK(args.length() == 2);
 
-  CONVERT_ARG_HANDLE_CHECKED(JSObject, object, 0);
+  CONVERT_ARG_HANDLE_CHECKED(JSReceiver, object, 0);
   CONVERT_ARG_HANDLE_CHECKED(Name, key, 1);
 
   Maybe<PropertyAttributes> maybe =
       JSReceiver::GetOwnPropertyAttributes(object, key);
   if (!maybe.IsJust()) return isolate->heap()->exception();
-  if (maybe.FromJust() == ABSENT) maybe = Just(DONT_ENUM);
+  if (maybe.FromJust() == ABSENT) return isolate->heap()->false_value();
   return isolate->heap()->ToBoolean((maybe.FromJust() & DONT_ENUM) == 0);
 }
 

test/mjsunit/harmony/proxies-property-is-enumerable.js

+// Copyright 2015 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.
+
+// Flags: --harmony-proxies
+
+var handler = {};
+var target = { a: 1 };
+var proxy = new Proxy(target, handler);
+
+assertTrue(target.propertyIsEnumerable('a'));
+assertTrue(proxy.propertyIsEnumerable('a'));
+assertFalse(target.propertyIsEnumerable('b'));
+assertFalse(proxy.propertyIsEnumerable('b'));
+
+handler.getOwnPropertyDescriptor = function(target, prop) {
+  return { configurable: true, enumerable: true, value: 10 };
+}
+assertTrue(target.propertyIsEnumerable('a'));
+assertTrue(proxy.propertyIsEnumerable('a'));
+assertFalse(target.propertyIsEnumerable('b'));
+assertTrue(proxy.propertyIsEnumerable('b'));
+
+handler.getOwnPropertyDescriptor = function(target, prop) {
+  return { configurable: true, enumerable: false, value: 10 };
+}
+assertTrue(target.propertyIsEnumerable('a'));
+assertFalse(proxy.propertyIsEnumerable('a'));
+assertFalse(target.propertyIsEnumerable('b'));
+assertFalse(proxy.propertyIsEnumerable('b'));