Add mobile safari simulator support in the testing scripts

tools/testing/dart/utils.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library utils;
 
 import 'dart:io';
 import 'dart:math' show min;
 import 'dart:convert';
 
@@ skipping 190 matching lines @@
           'linux': 'google-chrome'
         },
         'dartium': const {
           'windows': 'client\\tests\\dartium\\chrome.exe',
           'macos': 'client/tests/dartium/Chromium.app/Contents/MacOS/Chromium',
           'linux': 'client/tests/dartium/chrome'
         },
         'safari': const {
           'macos': '/Applications/Safari.app/Contents/MacOS/Safari'
         },
+        'safarimobilesim': const {
+          'macos': '/Applications/Xcode.app/Contents/Developer/Platforms/'
+                   'iPhoneSimulator.platform/Developer/Applications/'
+                   'iPhone Simulator.app/Contents/MacOS/iPhone Simulator'
+        },
         'ie9': const {
           'windows': 'C:\\Program Files\\Internet Explorer\\iexplore.exe'
         },
         'ie10': const {
           'windows': 'C:\\Program Files\\Internet Explorer\\iexplore.exe'
         }, 
         'ie11': const {
           'windows': 'C:\\Program Files\\Internet Explorer\\iexplore.exe'
         }};
     browserLocations['ff'] = browserLocations['firefox'];
@@ skipping 72 matching lines @@
 
 class UniqueObject {
   static int _nextId = 1;
   final int _hashCode;
 
   int get hashCode => _hashCode;
   operator==(other) => other is UniqueObject && _hashCode == other._hashCode;
 
   UniqueObject() : _hashCode = ++_nextId;
 }