[Sync] Add HasChildren() function and use it instead of GetFirstChildId()

chrome/browser/sync/glue/password_model_associator.cc

 // Copyright (c) 2011 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.
 
 #include "chrome/browser/sync/glue/password_model_associator.h"
 
 #include <set>
 
 #include "base/location.h"
 #include "base/stl_util.h"
@@ skipping 191 matching lines @@
 
   sync_api::ReadNode password_node(&trans);
   if (!password_node.InitByIdLookup(password_sync_id)) {
     LOG(ERROR) << "Server did not create the top-level password node. We "
                << "might be running against an out-of-date server.";
     return false;
   }
 
   // The sync model has user created nodes if the password folder has any
   // children.
-  *has_nodes = sync_api::kInvalidId != password_node.GetFirstChildId();
+  *has_nodes = password_node.HasChildren();
   return true;
 }
 
 void PasswordModelAssociator::AbortAssociation() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   base::AutoLock lock(abort_association_pending_lock_);
   abort_association_pending_ = true;
 }
 
 bool PasswordModelAssociator::CryptoReadyIfNecessary() {
@@ skipping 198 matching lines @@
     const std::string& password_element,
     const std::string& signon_realm) {
   return EscapePath(origin_url) + "|" +
          EscapePath(username_element) + "|" +
          EscapePath(username_value) + "|" +
          EscapePath(password_element) + "|" +
          EscapePath(signon_realm);
 }
 
 }  // namespace browser_sync