[Offline pages] Add navigation error handling to background loader.

chrome/browser/android/offline_pages/background_loader_offliner.h

 // Copyright 2016 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 CHROME_BROWSER_ANDROID_OFFLINE_PAGES_BACKGROUND_LOADER_OFFLINER_H_
 #define CHROME_BROWSER_ANDROID_OFFLINE_PAGES_BACKGROUND_LOADER_OFFLINER_H_
 
 #include <memory>
 
 #include "base/android/application_status_listener.h"
@@ skipping 25 matching lines @@
 
   // Offliner implementation.
   bool LoadAndSave(const SavePageRequest& request,
                    const CompletionCallback& callback) override;
   void Cancel() override;
 
   // WebContentsObserver implementation.
   void DidStopLoading() override;
   void RenderProcessGone(base::TerminationStatus status) override;
   void WebContentsDestroyed() override;
+  void DidFinishNavigation(
+      content::NavigationHandle* navigation_handle) override;
 
  protected:
   // Called to reset internal loader and observer state.
   virtual void ResetState();
 
  private:
   friend class TestBackgroundLoaderOffliner;
 
   enum SaveState { NONE, SAVING, DELETE_AFTER_SAVE };
 
@@ skipping 12 matching lines @@
   // Tracks pending request, if any.
   std::unique_ptr<SavePageRequest> pending_request_;
   // Callback when pending request completes.
   CompletionCallback completion_callback_;
   // ApplicationStatusListener to monitor if Chrome moves to the foreground.
   std::unique_ptr<base::android::ApplicationStatusListener> app_listener_;
   // Whether we are on a low-end device.
   bool is_low_end_device_;
   // Save state.
   SaveState save_state_;
+  // Error state.
+  bool is_error_;

[Dmitry Titov, 2017/01/25 19:36:55]

naming nit: perhaps it can be more explicit if it was is_error_page_ or
did_navigate_to_error_page_ 

[chili, 2017/01/31 20:07:37]

renamed to page_loading_state_ with enum because that seems better to also
convey whether it's simply loading failed vs no retry

 
   base::WeakPtrFactory<BackgroundLoaderOffliner> weak_ptr_factory_;
   DISALLOW_COPY_AND_ASSIGN(BackgroundLoaderOffliner);
 };
 
 }  // namespace offline_pages
 #endif  // CHROME_BROWSER_ANDROID_OFFLINE_PAGES_BACKGROUND_LOADER_OFFLINER_H_