mandoline: Add back/forward support and UI.

mandoline/ui/phone_ui/phone_browser_application_delegate.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 MANDOLINE_UI_PHONE_UI_PHONE_BROWSER_APPLICATION_DELEGATE_H_
 #define MANDOLINE_UI_PHONE_UI_PHONE_BROWSER_APPLICATION_DELEGATE_H_
 
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
 #include "components/view_manager/public/cpp/view_observer.h"
@@ skipping 39 matching lines @@
 
   // Overridden from mojo::ViewObserver:
   void OnViewBoundsChanged(mojo::View* view,
                            const mojo::Rect& old_bounds,
                            const mojo::Rect& new_bounds) override;
 
   // Overridden from web_view::mojom::WebViewClient:
   void TopLevelNavigate(mojo::URLRequestPtr request) override;
   void LoadingStateChanged(bool is_loading) override;
   void ProgressChanged(double progress) override;
+  void BackForwardChanged(web_view::mojom::ButtonState back_button,
+                          web_view::mojom::ButtonState forward_button) override;
   void TitleChanged(const mojo::String& title) override;
 
   // Overridden from mojo::InterfaceFactory<LaunchHandler>:
   void Create(mojo::ApplicationConnection* connection,
               mojo::InterfaceRequest<LaunchHandler> request) override;
 
   mojo::ApplicationImpl* app_;
   mojo::ViewTreeHostPtr host_;
 
   mojo::View* root_;
   mojo::View* content_;
   web_view::WebView web_view_;
 
   mojo::String default_url_;
 
   mojo::WeakBindingSet<LaunchHandler> launch_handler_bindings_;
 
   DISALLOW_COPY_AND_ASSIGN(PhoneBrowserApplicationDelegate);
 };
 
 }  // namespace mandoline
 
 #endif  // MANDOLINE_UI_PHONE_UI_PHONE_BROWSER_APPLICATION_DELEGATE_H_