Polymer/polymer — pull request #286 by jmesserly (2013-09-21 01:07:52+00:00)
Title: remove extra argument to unbindProperty that was ignored

unregisterObserver only takes a "name" argument:

```js
function unregisterObserver(element, name) {
var o$ = getElementObservers(element);
if (o$ && o$[name]) {
o$[name].close();
o$[name] = null;
return true;
}
}
```