Eliminate usage of InterfacePtr::WaitForIncomingResponse.

services/catalog/public/interfaces/catalog.mojom

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 module catalog.mojom;
 
 struct Entry {
   string name;
   string display_name;
 };
 
 interface Catalog {
   // Returns the catalog entries for the specified mojo names.
   // If |names| is null, all available entries are returned.
+  [Sync]
   GetEntries(array<string>? names) => (array<Entry> entries);
 
   // Returns the entry(ies) for applications that export to the caller the
   // specified class.
   GetEntriesProvidingClass(string clazz) => (array<Entry> entries);
 
   // Returns the entry(ies) for applications that can consume content of the
   // specified MIME type.
   GetEntriesConsumingMIMEType(string mime_type) => (array<Entry> entries);
 
   // Returns the entry(ies) for applications that can handle links with the
   // specified scheme.
   GetEntriesSupportingScheme(string protocol_scheme) => (array<Entry> entries);
 };