[ios] Wait for sync query to return before displaying history

ios/chrome/browser/ui/history/history_service_facade.h

Index: ios/chrome/browser/ui/history/history_service_facade.h
diff --git a/ios/chrome/browser/ui/history/history_service_facade.h b/ios/chrome/browser/ui/history/history_service_facade.h
index bb371864a55d47cd682ab45e686f89b1edb2fb9e..a6580941a629dde53d7ef31e532c16b56edc79ff 100644
--- a/ios/chrome/browser/ui/history/history_service_facade.h
+++ b/ios/chrome/browser/ui/history/history_service_facade.h
@@ -46,8 +46,13 @@ class HistoryServiceFacade : public history::HistoryServiceObserver {
     base::string16 query;
     base::string16 query_start_time;
     base::string16 query_end_time;
+    // true if all local history from History service has been retrieved.
     bool finished;
+    // true if a query to WebHistoryService has returned successfully.
+    bool sync_returned;
+    // true if results from WebHistoryService have been retrieved.
     bool has_synced_results;
+    // true if all remote history from WebHistoryService has been retrieved.
     bool sync_finished;
     std::vector<history::HistoryEntry> entries;
   };