Fix the Download Notifications for Offline Pages to indicate bytes loaded.

components/offline_pages/core/background/cleanup_task_unittest.cc

Index: components/offline_pages/core/background/cleanup_task_unittest.cc
diff --git a/components/offline_pages/core/background/cleanup_task_unittest.cc b/components/offline_pages/core/background/cleanup_task_unittest.cc
index acfb33b128469775f7c63ce2426e7d9d0a9ba67a..84529066c871fb87c30053d13c1103babb341991 100644
--- a/components/offline_pages/core/background/cleanup_task_unittest.cc
+++ b/components/offline_pages/core/background/cleanup_task_unittest.cc
@@ -58,6 +58,9 @@ class RequestNotifierStub : public RequestNotifier {
     total_expired_requests_++;
   }
 
+  void NotifyNetworkProgress(const SavePageRequest& request,
+                             int64_t received_bytes) override {}
+
   const SavePageRequest& last_expired_request() {
     return last_expired_request_;
   }