Remove the Proxy enumerate trap

test/mjsunit/for-in-opt.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 --allow-natives-syntax --expose-debug-as debug
 
 "use strict";
 
 // Test non-JSObject receiver.
 function f(o) {
@@ skipping 10 matching lines @@
 %OptimizeFunctionOnNextCall(f);
 assertEquals(["0","1","2"], f("bla"));
 
 // Test the lazy deopt points.
 var keys = ["a", "b", "c", "d"];
 var has_keys = [];
 var deopt_has = false;
 var deopt_enum = false;
 
 var handler = {
-  enumerate(target) {
+  ownKeys() {
     if (deopt_enum) {
       %DeoptimizeFunction(f2);
       deopt_enum = false;
     }
-    return keys[Symbol.iterator]();
+    return keys;
   },
+  getOwnPropertyDescriptor() { return { enumerable: true, configurable: true }},
 
   has(target, k) {
     if (deopt_has) {
       %DeoptimizeFunction(f2);
       deopt_has = false;
     }
     has_keys.push(k);
-    return {value: 10, configurable: true, writable: false, enumerable: true};
+    return true;
   }
 };
 
 
 var proxy = new Proxy({}, handler);
 var o = {__proto__: proxy};
 
 function f2(o) {
   var result = [];
   for (var i in o) {
@@ skipping 73 matching lines @@
 
 var Debug = debug.Debug;
 
 function listener(event, exec_state, event_data, data) {
   if (event == Debug.DebugEvent.Break) {
     %DeoptimizeFunction(f5);
   }
 }
 
 var handler3 = {
-  enumerate(target) {
-    return ["a", "b"][Symbol.iterator]();
-  },
+  ownKeys() { return ["a", "b"] },
+  getOwnPropertyDescriptor() { return { enumerable: true, configurable: true }},
 
   has(target, k) {
     if (k == "a") count++;
     if (x) %ScheduleBreak();
-    return {value: 10, configurable: true, writable: false, enumerable: true};
+    return true;
   }
 };
 
 var proxy3 = new Proxy({}, handler3);
 var o3 = {__proto__: proxy3};
 
 function f5() {
   for (var p in o3) {
     print(p);
   }
 }
 
 x = false;
 
 f5(); f5(); f5();
 %OptimizeFunctionOnNextCall(f5);
 x = true;
 count = 0;
 Debug.setListener(listener);
 f5();
 Debug.setListener(null);
 assertEquals(1, count);