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

components/offline_pages/core/snapshot_controller.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 COMPONENTS_OFFLINE_PAGES_CORE_SNAPSHOT_CONTROLLER_H_
 #define COMPONENTS_OFFLINE_PAGES_CORE_SNAPSHOT_CONTROLLER_H_
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/single_thread_task_runner.h"
@@ skipping 64 matching lines @@
 
   // Stops current session, no more Client::StartSnapshot calls will be
   // invoked from the SnapshotController until current session is Reset().
   // Called by Client, for example when it encounters an error loading the page.
   void Stop();
 
   // The way for Client to report that previously started snapshot is
   // now completed (so the next one can be started).
   void PendingSnapshotCompleted();
 
-  // Invoked from WebContentObserver::DocumentAvailableInMainFrame
+  // Invoked from WebContentsObserver::DocumentLoadedInFrame when the frame
+  // is the main frame.
+  void DocumentLoadedInMainFrame();
+
+  // Invoked from WebContentsObserver::DidStopLoading.
+  void DidStopLoading();
+
+  // Invoked from WebContentsObserver::DocumentAvailableInMainFrame.
+  // Maps to DocumentLoadedInMainFrame for now.
   void DocumentAvailableInMainFrame();
 
-  // Invoked from WebContentObserver::DocumentOnLoadCompletedInMainFrame
+  // Invoked from WebContentsObserver::DocumentOnLoadCompletedInMainFrame.
+  // Maps to DidStopLoading for now.
   void DocumentOnLoadCompletedInMainFrame();
 
-  int64_t GetDelayAfterDocumentAvailableForTest();
-  int64_t GetDelayAfterDocumentOnLoadCompletedForTest();
+  int64_t GetDelayAfterDocumentLoadedForTest();
+  int64_t GetDelayAfterLoadCompletedForTest();
 
   PageQuality current_page_quality() const { return current_page_quality_; }
 
  private:
   void MaybeStartSnapshot(PageQuality updated_page_quality);
   void MaybeStartSnapshotThenStop();
 
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
   // Client owns this class.
   SnapshotController::Client* client_;
   SnapshotController::State state_;
-  int64_t delay_after_document_available_ms_;
-  int64_t delay_after_document_on_load_completed_ms_;
+  int64_t delay_after_document_loaded_ms_;
+  int64_t delay_after_load_completed_ms_;
 
   // The expected quality of a snapshot taken at the moment this value is
   // queried.
   PageQuality current_page_quality_ = PageQuality::POOR;
 
   base::WeakPtrFactory<SnapshotController> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(SnapshotController);
 };
 
 }  // namespace offline_pages
 
 #endif  // COMPONENTS_OFFLINE_PAGES_CORE_SNAPSHOT_CONTROLLER_H_