[Offline pages] Update background loader to override the WebContentsObserver methods expected

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 29 matching lines @@
       content::WebContents* contents);
 
   // Offliner implementation.
   bool LoadAndSave(const SavePageRequest& request,
                    const CompletionCallback& completion_callback,
                    const ProgressCallback& progress_callback) override;
   void Cancel(const CancelCallback& callback) override;
   bool HandleTimeout(const SavePageRequest& request) override;
 
   // WebContentsObserver implementation.
-  void DocumentLoadedInFrame(content::RenderFrameHost* render_frame) override;
-  void DidStopLoading() override;
+  void DocumentAvailableInMainFrame() override;
+  void DocumentOnLoadCompletedInMainFrame() override;
   void RenderProcessGone(base::TerminationStatus status) override;
   void WebContentsDestroyed() override;
   void DidFinishNavigation(
       content::NavigationHandle* navigation_handle) override;
 
   // SnapshotController::Client implementation.
   void StartSnapshot() override;
 
   void SetPageDelayForTest(long delay_ms);
   void OnNetworkBytesChanged(int64_t bytes);
@@ skipping 46 matching lines @@
 
   // Callback for cancel.
   CancelCallback cancel_callback_;
 
   base::WeakPtrFactory<BackgroundLoaderOffliner> weak_ptr_factory_;
   DISALLOW_COPY_AND_ASSIGN(BackgroundLoaderOffliner);
 };
 
 }  // namespace offline_pages
 #endif  // CHROME_BROWSER_ANDROID_OFFLINE_PAGES_BACKGROUND_LOADER_OFFLINER_H_