[Navigation Experiment] Add WKBasedNavigationManagerImpl.

ios/web/navigation/web_view_navigation_proxy_impl.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_NAVIGATION_WEB_VIEW_NAVIGATION_PROXY_IMPL_H_
+#define IOS_WEB_NAVIGATION_WEB_VIEW_NAVIGATION_PROXY_IMPL_H_
+
+#include "ios/web/navigation/web_view_navigation_proxy.h"
+
+@class NSarray;
+@class WKBackForwardListItem;
+@class WKWebView;
+
+namespace web {
+
+class WebViewNavigationProxyImpl : public WebViewNavigationProxy {
+ public:
+  WebViewNavigationProxyImpl(WKWebView* web_view);
+  ~WebViewNavigationProxyImpl() override {}
+
+  bool HasWebView() const override;
+
+  bool CanGoBack() const override;
+  bool CanGoForward() const override;
+  void GoBack() const override;
+  void GoForward() const override;
+  void GoToBackForwardListItem(WKBackForwardListItem* item) const override;
+
+  WKBackForwardListItem* GetCurrentItem() const override;
+  NSArray<WKBackForwardListItem*>* GetBackList() const override;
+  NSArray<WKBackForwardListItem*>* GetForwardList() const override;
+  WKBackForwardListItem* GetItemAtOffset(int offset) const override;
+
+  void SetWebView(WKWebView* web_view);
+
+ private:
+  WKWebView* web_view_;
+};
+
+}  // namespace web
+
+#endif  // IOS_WEB_NAVIGATION_WEB_VIEW_NAVIGATION_PROXY_IMPL_H_