Upstream the iOS web_shell and supporting code

ios/ios.gyp

 # Copyright 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 {
   'variables': {
     'chromium_code': 1,
    },
   'targets': [
     {
       'target_name': 'ios',
       'type': 'none',
       'dependencies': [
         'chrome/ios_chrome_tests.gyp:*',
         'crnet/crnet.gyp:*',
         'crnet/crnet_pack.gyp:*',
         'crnet/crnet_consumer/crnet_consumer.gyp:*',
         'net/ios_net.gyp:*',
         'net/ios_net_unittests.gyp:*',
         'provider/ios_provider_chrome.gyp:*',
         'provider/ios_provider_web.gyp:*',
         'testing/ios_testing.gyp:*',
         'web/ios_web.gyp:*',
+        'web/ios_web_shell.gyp:*',
         'web/ios_web_unittests.gyp:*',
       ],
     },
   ],
 }