Remove CWV class and move setting User Agent to CWVWebViewConfiguration.

ios/web_view/internal/web_view_web_main_parts.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_WEB_VIEW_INTERNAL_WEB_VIEW_WEB_MAIN_PARTS_H_
 #define IOS_WEB_VIEW_INTERNAL_WEB_VIEW_WEB_MAIN_PARTS_H_
 
 #include <memory>
 
 #include "ios/web/public/app/web_main_parts.h"
 
 @protocol CWVDelegate;
 
 namespace ios_web_view {
-class WebViewBrowserState;
 
 // WebView implementation of WebMainParts.
 class WebViewWebMainParts : public web::WebMainParts {
  public:
   WebViewWebMainParts();
   ~WebViewWebMainParts() override;
 
   // WebMainParts implementation.
   void PreMainMessageLoopRun() override;
-
-  // Returns the WebViewBrowserState for this embedder.
-  WebViewBrowserState* browser_state() const { return browser_state_.get(); }
-
-  // Returns the off the record WebViewBrowserState for this embedder.
-  WebViewBrowserState* off_the_record_browser_state() const {
-    return off_the_record_browser_state_.get();
-  }
-
- private:
-  // The BrowserState for this embedder.
-  std::unique_ptr<WebViewBrowserState> browser_state_;
-
-  // Off The Record BrowserState for this embedder.
-  std::unique_ptr<WebViewBrowserState> off_the_record_browser_state_;
 };
 
 }  // namespace ios_web_view
 
 #endif  // IOS_WEB_VIEW_INTERNAL_WEB_VIEW_WEB_MAIN_PARTS_H_