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

chrome/browser/sync/glue/autofill_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/autofill_model_associator.h"
 
 #include <functional>
 #include <vector>
 
 #include "base/location.h"
@@ skipping 369 matching lines @@
 
   sync_api::ReadNode autofill_node(&trans);
   if (!autofill_node.InitByIdLookup(autofill_sync_id)) {
     LOG(ERROR) << "Server did not create the top-level autofill node. We "
                << "might be running against an out-of-date server.";
     return false;
   }
 
   // The sync model has user created nodes if the autofill folder has any
   // children.
-  *has_nodes = sync_api::kInvalidId != autofill_node.GetFirstChildId();
+  *has_nodes = autofill_node.HasChildren();
   return true;
 }
 
 void AutofillModelAssociator::AbortAssociation() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   base::AutoLock lock(abort_association_pending_lock_);
   abort_association_pending_ = true;
 }
 
 const std::string*
@@ skipping 119 matching lines @@
 bool AutofillModelAssociator::CryptoReadyIfNecessary() {
   // We only access the cryptographer while holding a transaction.
   sync_api::ReadTransaction trans(FROM_HERE, sync_service_->GetUserShare());
   syncable::ModelTypeSet encrypted_types;
   encrypted_types = sync_api::GetEncryptedTypes(&trans);
   return encrypted_types.count(syncable::AUTOFILL) == 0 ||
          sync_service_->IsCryptographerReady(&trans);
 }
 
 }  // namespace browser_sync