Introduce the WebState iOS provider interface.

ios/ios_web.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': 'metro_utils',
-      'type': 'static_library',
-      'dependencies': [
-        'installer_util',
-        '../base/base.gyp:base',
-      ],
+      'target_name': 'ios_provider_web',
+      'type': 'none',
       'include_dirs': [
         '..',
       ],
       'sources': [
-        'browser/metro_utils/metro_chrome_win.cc',
-        'browser/metro_utils/metro_chrome_win.h',
+        'public/provider/web/web_state.h',
+        'public/provider/web/web_state_user_data.h',
+      ],
+      'dependencies': [
+        'ios_base.gyp:ios_consumer_base',
       ],
     },
   ],
 }