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

ios/public/provider/web/web_ui_ios_controller.h

 // Copyright 2014 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.
 
 #ifndef IOS_PUBLIC_PROVIDER_WEB_WEB_UI_IOS_CONTROLLER_H_
 #define IOS_PUBLIC_PROVIDER_WEB_WEB_UI_IOS_CONTROLLER_H_
 
-#include "base/strings/string16.h"
-
-class GURL;
-
-namespace base {
-class ListValue;
-}
-
-namespace web {
-
-class WebUIIOS;
-
-// A WebUIIOS page is controlled by the embedder's WebUIIOSController object. It
-// manages the data source and message handlers.
-class WebUIIOSController {
- public:
-  explicit WebUIIOSController(WebUIIOS* web_ui) : web_ui_(web_ui) {}
-  virtual ~WebUIIOSController() {}
-
-  // Allows the controller to override handling all messages from the page.
-  // Return true if the message handling was overridden.
-  virtual bool OverrideHandleWebUIIOSMessage(const GURL& source_url,
-                                             const std::string& message,
-                                             const base::ListValue& args);
-
-  WebUIIOS* web_ui() const { return web_ui_; }
-
- private:
-  WebUIIOS* web_ui_;
-};
-
-}  // namespace web
+// TODO(crbug.com/524467): Remove this file once downstream code is switched to
+// use correct header.
+#include "ios/web/public/webui/web_ui_ios_controller.h"
 
 #endif  // IOS_PUBLIC_PROVIDER_WEB_WEB_UI_IOS_CONTROLLER_H_