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

chrome/browser/android/offline_pages/prerendering_loader.cc

Index: chrome/browser/android/offline_pages/prerendering_loader.cc
diff --git a/chrome/browser/android/offline_pages/prerendering_loader.cc b/chrome/browser/android/offline_pages/prerendering_loader.cc
index 0b2f878764963cadf74a4cf1ec95240527f95c2f..d213621bf5ae173733e945ce66d28164586cb3d1 100644
--- a/chrome/browser/android/offline_pages/prerendering_loader.cc
+++ b/chrome/browser/android/offline_pages/prerendering_loader.cc
@@ -151,7 +151,7 @@ void PrerenderingLoader::OnPrerenderStopLoading() {
   DCHECK(adapter_->GetWebContents());
   // Inform SnapshotController of OnLoad event so it can determine
   // when to consider it really LOADED.
-  snapshot_controller_->DocumentOnLoadCompletedInMainFrame();
+  snapshot_controller_->DidStopLoading();
 }
 
 void PrerenderingLoader::OnPrerenderDomContentLoaded() {
@@ -166,7 +166,7 @@ void PrerenderingLoader::OnPrerenderDomContentLoaded() {
       // Inform SnapshotController of DomContentLoaded event so it can
       // determine when to consider it really LOADED (e.g., some multiple
       // second delay from this event).
-      snapshot_controller_->DocumentAvailableInMainFrame();
+      snapshot_controller_->DocumentLoadedInMainFrame();
     }
   }
 }