sync: Better iteration in GenericChangeProcessor

sync/syncable/entry.h

Index: sync/syncable/entry.h
diff --git a/sync/syncable/entry.h b/sync/syncable/entry.h
index f9d3f90cc97bef33414c8d690f89b0bec246ad53..26ccc0a7b8a6b258baae38618d62b10c1ab88f24 100644
--- a/sync/syncable/entry.h
+++ b/sync/syncable/entry.h
@@ -109,6 +109,12 @@ class SYNC_EXPORT Entry {
   Id GetSuccessorId() const;
   Id GetFirstChildId() const;
 
+  // Returns a vector of this node's children's handles.
+  // Clears |result| if there are no children.  If this node is of a type that
+  // supports user-defined ordering then the resulting vector will be in the
+  // proper order.
+  void GetChildHandles(std::vector<int64>* result) const;
+
   inline bool ExistsOnClientBecauseNameIsNonEmpty() const {
     DCHECK(kernel_);
     return !kernel_->ref(NON_UNIQUE_NAME).empty();