mandoline: Add back/forward support and UI.

components/web_view/web_view_impl.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 COMPONENTS_WEB_VIEW_WEB_VIEW_IMPL_H_
 #define COMPONENTS_WEB_VIEW_WEB_VIEW_IMPL_H_
 
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/memory/scoped_vector.h"
 #include "components/view_manager/public/cpp/view_observer.h"
 #include "components/view_manager/public/cpp/view_tree_delegate.h"
 #include "components/web_view/frame_devtools_agent_delegate.h"
 #include "components/web_view/frame_tree_delegate.h"
 #include "components/web_view/public/interfaces/web_view.mojom.h"
 #include "third_party/mojo/src/mojo/public/cpp/bindings/strong_binding.h"
 
 namespace mojo {
 class ApplicationImpl;
 }
 
 namespace web_view {
 
 class Frame;
 class FrameTree;
 class FrameDevToolsAgent;
 class HTMLMessageEvent;
+class NavigationEntry;
 class PendingWebViewLoad;
 
 class WebViewImpl : public mojom::WebView,
                     public mojo::ViewTreeDelegate,
                     public mojo::ViewObserver,
                     public FrameTreeDelegate,
                     public FrameDevToolsAgentDelegate {
  public:
   WebViewImpl(mojo::ApplicationImpl* app,
               mojom::WebViewClientPtr client,
               mojo::InterfaceRequest<WebView> request);
   ~WebViewImpl() override;
 
  private:
   friend class PendingWebViewLoad;
 
   // See description above |pending_load_| for details.
   void OnLoad();
 
+  void UpdateBackForwardEnableState();
+
   // Overridden from WebView:
   void LoadRequest(mojo::URLRequestPtr request) override;
   void GetViewTreeClient(
       mojo::InterfaceRequest<mojo::ViewTreeClient> view_tree_client)
           override;
+  void GoBack() override;
+  void GoForward() override;
 
   // Overridden from mojo::ViewTreeDelegate:
   void OnEmbed(mojo::View* root) override;
   void OnConnectionLost(mojo::ViewTreeConnection* connection) override;
 
   // Overridden from mojo::ViewObserver:
   void OnViewBoundsChanged(mojo::View* view,
                            const mojo::Rect& old_bounds,
                            const mojo::Rect& new_bounds) override;
   void OnViewDestroyed(mojo::View* view) override;
@@ skipping 21 matching lines @@
   mojo::View* content_;
   scoped_ptr<FrameTree> frame_tree_;
 
   // When LoadRequest() is called a PendingWebViewLoad is created to wait for
   // state needed to process the request. When the state is obtained OnLoad()
   // is invoked.
   scoped_ptr<PendingWebViewLoad> pending_load_;
 
   scoped_ptr<FrameDevToolsAgent> devtools_agent_;
 
+  // It would be nice if mojo::URLRequest were cloneable; however, its use of
+  // ScopedDataPipieConsumerHandle means that it isn't.
+  ScopedVector<NavigationEntry> back_list_;

[msw, 2015/09/04 22:05:00]

nit: |backward_list_| to match |forward_list_|

+  ScopedVector<NavigationEntry> forward_list_;

[msw, 2015/09/04 22:05:00]

Consider having a single list and an iterator for the current element.
(that should make going back/forward cleaner; no juggling list entries)

+
+  // The request which is either currently loading or completed loading. On a

[msw, 2015/09/04 22:05:00]

nit: consider "The current request, which may be loading or completed."

+  // new navigation where this

[msw, 2015/09/04 22:05:00]

Incomplete sentence

+  scoped_ptr<NavigationEntry> current_page_request_;

[msw, 2015/09/04 22:05:00]

nit: consider |current_request_|

+
   DISALLOW_COPY_AND_ASSIGN(WebViewImpl);
 };
 
 }  // namespace web_view
 
 #endif  // COMPONENTS_WEB_VIEW_WEB_VIEW_IMPL_H_