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

ios/chrome/browser/ui/webui/version_handler.cc

 // 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.
 
 #include "ios/chrome/browser/ui/webui/version_handler.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/values.h"
 #include "components/version_ui/version_handler_helper.h"
 #include "components/version_ui/version_ui_constants.h"
-#include "ios/public/provider/web/web_ui_ios.h"
+#include "ios/web/public/webui/web_ui_ios.h"
 #include "ui/base/l10n/l10n_util.h"
 
 VersionHandler::VersionHandler() {}
 
 VersionHandler::~VersionHandler() {}
 
 void VersionHandler::RegisterMessages() {
   web_ui()->RegisterMessageCallback(
       version_ui::kRequestVersionInfo,
       base::Bind(&VersionHandler::HandleRequestVersionInfo,
                  base::Unretained(this)));
 }
 
 void VersionHandler::HandleRequestVersionInfo(const base::ListValue* args) {
   // Respond with the variations info immediately.
   web_ui()->CallJavascriptFunction(version_ui::kReturnVariationInfo,
                                    *version_ui::GetVariationsList());
 }