[MD History] Fix deletion in heavily scrolled list.

components/history/core/browser/web_history_service.cc

Index: components/history/core/browser/web_history_service.cc
diff --git a/components/history/core/browser/web_history_service.cc b/components/history/core/browser/web_history_service.cc
index 35d97b85957559f9ce58aefca4d678ebdef09449..d66a39c313cee3bd02fdaedcdab804315d94fd23 100644
--- a/components/history/core/browser/web_history_service.cc
+++ b/components/history/core/browser/web_history_service.cc
@@ -563,13 +563,14 @@ void WebHistoryService::ExpireHistoryCompletionCallback(
     if (response_value)
       response_value->GetString("version_info", &server_version_info_);
   }
-  callback.Run(response_value.get() && success);
 
   // Inform the observers about the history deletion.
   if (response_value.get() && success) {
     FOR_EACH_OBSERVER(WebHistoryServiceObserver, observer_list_,
                       OnWebHistoryDeleted());
   }
+
+  callback.Run(response_value.get() && success);
 }
 
 void WebHistoryService::AudioHistoryCompletionCallback(