Initialize CRIWVWebView with Configuration object instead of browserState.

ios/web_view/public/criwv_website_data_store.h

+// Copyright 2017 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_PUBLIC_CRIWV_WEBSITE_DATA_STORE_H_
+#define IOS_WEB_VIEW_PUBLIC_CRIWV_WEBSITE_DATA_STORE_H_
+
+#import <Foundation/Foundation.h>
+
+// Controls persistence of website data such as cookies, caches, and local
+// storage.
+@interface CRIWVWebsiteDataStore : NSObject
+
+// Whether or not this data store persists data to disk.
+@property(readonly, getter=isPersistent) BOOL persistent;
+
+// Persistent data store which stores all data on disk.
++ (instancetype)defaultDataStore;
+// Ephemeral data store that never stores data on disk.
++ (instancetype)nonPersistentDataStore;
+
+@end
+
+#endif  // IOS_WEB_VIEW_PUBLIC_CRIWV_WEBSITE_DATA_STORE_H_