Unit tests for attempt manager.

BUG=164227
TEST=No

Review URL: https://chromiumcodereview.appspot.com/23751004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@222189 0039d316-1c4b-4281-b951-d872f2087c98

chrome/test/data/webui/test_api.js

@@ -572,7 +572,6 @@ var testing = {};
     }
 
     var fieldName = path[path.length-1];
-    assertEquals(undefined, namespace[fieldName]);
     namespace[fieldName] = theFunction;
   }