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

components/offline_pages/core/snapshot_controller.h

Index: components/offline_pages/core/snapshot_controller.h
diff --git a/components/offline_pages/core/snapshot_controller.h b/components/offline_pages/core/snapshot_controller.h
index 36e1680a6f03f515a7c0305eef0669a6602796d6..b02de524f886d85afc0a6ad4d188dfa98fb4cf2a 100644
--- a/components/offline_pages/core/snapshot_controller.h
+++ b/components/offline_pages/core/snapshot_controller.h
@@ -82,14 +82,23 @@ class SnapshotController {
   // 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_; }
 
@@ -101,8 +110,8 @@ class SnapshotController {
   // 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.