[js-perf-test] Adding micro benchmarks for for-in and keys patterns.

test/js-perf-test/Keys/run.js

 // 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.
 
-
 load('../base.js');
-load('assign.js');
+load('keys.js');
 
 var success = true;
 
 function PrintResult(name, result) {
-  print(name + '-Object(Score): ' + result);
+  print(name + '-Keys(Score): ' + result);
 }
 
-
 function PrintError(name, error) {
   PrintResult(name, error);
   success = false;
 }
 
-
 BenchmarkSuite.config.doWarmup = undefined;
 BenchmarkSuite.config.doDeterministic = undefined;
 
-BenchmarkSuite.RunSuites({ NotifyResult: PrintResult,
-                           NotifyError: PrintError });
+BenchmarkSuite.RunSuites({NotifyResult: PrintResult, NotifyError: PrintError});