Remove unnecessary updateStyleIfNeeded call.

I'm not really sure what this was originally from, but it clearly
isn't needed anymore.

Review URL: https://codereview.chromium.org/82713007

git-svn-id: svn://svn.chromium.org/blink/trunk@162566 bbb929c8-8fbe-4397-9dbb-9b2b20218538