Offline Pages: Replace Observer::OfflinePageModelChanged with OfflinePageAdded.

components/ntp_snippets/offline_pages/offline_page_proxy.h

Index: components/ntp_snippets/offline_pages/offline_page_proxy.h
diff --git a/components/ntp_snippets/offline_pages/offline_page_proxy.h b/components/ntp_snippets/offline_pages/offline_page_proxy.h
index a3fa62ea0ca8f57fc74d54cbd400f12249a7fb0c..7e4c6ae426a0758bb35d513529a3576f57dafcb7 100644
--- a/components/ntp_snippets/offline_pages/offline_page_proxy.h
+++ b/components/ntp_snippets/offline_pages/offline_page_proxy.h
@@ -60,7 +60,9 @@ class OfflinePageProxy : public offline_pages::OfflinePageModel::Observer,
 
   // OfflinePageModel::Observer implementation.
   void OfflinePageModelLoaded(offline_pages::OfflinePageModel* model) override;
-  void OfflinePageModelChanged(offline_pages::OfflinePageModel* model) override;
+  void OfflinePageAdded(offline_pages::OfflinePageModel* model,
+                        offline_pages::SavePageResult result,
+                        const offline_pages::OfflinePageItem* item) override;
   void OfflinePageDeleted(int64_t offline_id,
                           const offline_pages::ClientId& client_id) override;