Apply object updates from the network without blowing away object identity or UI attributes.

Tools/GardeningServer/model/ct-repository-commit-list.html

+<!--
+Copyright 2014 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.
+-->
+
+<script>
+function CTRepositoryCommitList(repository, commits) {
+  this.name = repository;
+  this.fingerprint = repository;
+  this.range = this._displayRange(commits);
+  this.commits = commits;
+  this.expanded = false;
+}
+
+CTRepositoryCommitList.prototype._displayRange = function(commits) {
+  return commits.first().revision + " : " + commits.last().revision;
+};
+
+CTRepositoryCommitList.uiStateProperties = ['expanded'];
+
+</script>