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

chrome/browser/sync/glue/bookmark_change_processor.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/bookmark_change_processor.h"
 
 #include <stack>
 #include <vector>
 
 #include "base/location.h"
@@ skipping 72 matching lines @@
 }
 
 void BookmarkChangeProcessor::RemoveOneSyncNode(
     sync_api::WriteTransaction* trans, const BookmarkNode* node) {
   sync_api::WriteNode sync_node(trans);
   if (!model_associator_->InitSyncNodeFromChromeId(node->id(), &sync_node)) {
     error_handler()->OnUnrecoverableError(FROM_HERE, std::string());
     return;
   }
   // This node should have no children.
-  DCHECK(sync_node.GetFirstChildId() == sync_api::kInvalidId);
+  DCHECK(!sync_node.HasChildren());
   // Remove association and delete the sync node.
   model_associator_->Disassociate(sync_node.GetId());
   sync_node.Remove();
 }
 
 void BookmarkChangeProcessor::RemoveSyncNodeHierarchy(
     const BookmarkNode* topmost) {
   sync_api::WriteTransaction trans(FROM_HERE, share_handle());
 
   // Later logic assumes that |topmost| has been unlinked.
@@ skipping 458 matching lines @@
     const BookmarkNode* bookmark_node,
     BookmarkModel* model,
     sync_api::WriteNode* sync_node) {
   std::vector<unsigned char> favicon_bytes;
   EncodeFavicon(bookmark_node, model, &favicon_bytes);
   if (!favicon_bytes.empty())
     sync_node->SetFaviconBytes(favicon_bytes);
 }
 
 }  // namespace browser_sync