IE <= 9 failure

[OlsonDev]

I have a page using KnockoutJS. This polyfill breaks because of the implementation of isInited(). I'm assuming KO is cloning the element somehow that's not compatible with your polyfill.

The current implementation looks like this:

isInited: function(progress) {
    return progress.getAttribute('role') === 'progressbar';
}

I changed it to look like this and it fixed it:

isInited: function(progress) {
    return 'position' in progress;
}

I'd submit a pull request but I'm not certain this is the best solution.