[Sheriff-o-matic] Use likely_revisions instead of first_failing/last_passing

Tools/GardeningServer/ui/test/ct-commit-list-tests.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.
 -->
 
 <link rel="import" href="../ct-commit-list.html">
 
 <link rel="import" href="../../model/ct-commit-list-mock.html">
 
@@ skipping 21 matching lines @@
       assert.lengthOf(commits, 0);
     });
 
     describe('expanded test', function() {
       beforeEach(function(done) {
         list.commitList.repositories.first().expanded = true;
         setTimeout(done);
       });
 
       it('should show commit when expanded', function() {
-        assert.lengthOf(list.shadowRoot.querySelectorAll('ct-commit'), 1);
+        assert.lengthOf(list.shadowRoot.querySelectorAll('ct-commit'), 2);
       });
     });
   });
 });
 
 })()
 </script>