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

ios/chrome/browser/ui/webui/flags_ui.h

 // 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.
 
 #ifndef IOS_CHROME_BROWSER_UI_WEBUI_FLAGS_UI_H_
 #define IOS_CHROME_BROWSER_UI_WEBUI_FLAGS_UI_H_
 
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
-#include "ios/public/provider/web/web_ui_ios_controller.h"
+#include "ios/web/public/webui/web_ui_ios_controller.h"
 #include "ui/base/layout.h"
 
 namespace base {
 class RefCountedMemory;
 }
 
 class BaseFlagsUI : public web::WebUIIOSController {
  public:
   enum FlagsUIKind {
     FLAGS_UI_GENERIC,
@@ skipping 26 matching lines @@
 class AppleFlagsUI : public BaseFlagsUI {
  public:
   explicit AppleFlagsUI(web::WebUIIOS* web_ui);
   ~AppleFlagsUI() override;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(AppleFlagsUI);
 };
 
 #endif  // IOS_CHROME_BROWSER_UI_WEBUI_FLAGS_UI_H_