Removing unecessary resize listener

monitorScrollValue is only called with `ViewportMetrics.refreshScrollValues` (https://github.com/facebook/react/blob/master/src/browser/ReactBrowserEventEmitter.js#L333-L334) and the window scroll properties (scrollTop and scrollLeft) don't change on resize (from my testings), so there is no need to listen for window resizes. I also tried to see why the resize listener was added from the history but it was introduced on the initial commits. I created a simple page that shows that http://jsbin.com/nuhice, open the console.