[ios] Moved WebUI provider code to ios/web.

ios/web/BUILD.gn

 # Copyright 2015 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.
 
 import("//ios/build/config.gni")
 import("//ios/web/js_compile.gni")
 import("//testing/test.gni")
 import("//tools/grit/grit_rule.gni")
 
 source_set("web") {
@@ skipping 145 matching lines @@
     "public/web_state/web_state_delegate.h",
     "public/web_state/web_state_delegate_bridge.h",
     "public/web_state/web_state_observer.h",
     "public/web_state/web_state_observer_bridge.h",
     "public/web_state/web_state_policy_decider.h",
     "public/web_state/web_state_user_data.h",
     "public/web_thread.h",
     "public/web_thread_delegate.h",
     "public/web_ui_ios_data_source.h",
     "public/web_view_creation_util.h",
+    "public/webui/web_ui_ios.h",
+    "public/webui/web_ui_ios_controller.cc",
+    "public/webui/web_ui_ios_controller.h",
+    "public/webui/web_ui_ios_controller_factory.h",
+    "public/webui/web_ui_ios_message_handler.cc",
+    "public/webui/web_ui_ios_message_handler.h",
     "string_util.cc",
     "url_scheme_util.mm",
     "url_util.cc",
     "web_kit_constants.cc",
     "web_state/blocked_popup_info.h",
     "web_state/blocked_popup_info.mm",
     "web_state/context_menu_params.mm",
     "web_state/credential.cc",
     "web_state/crw_pass_kit_downloader.h",
     "web_state/crw_pass_kit_downloader.mm",
@@ skipping 382 matching lines @@
 }
 
 grit("resources") {
   source = "ios_web_resources.grd"
   use_qualified_include = true
   outputs = [
     "grit/ios_web_resources.h",
     "ios_web_resources.pak",
   ]
 }