Remove a VS2010 workaround.

We require 2013 these days. No intended behavior change.

BUG=none

Review URL: https://codereview.chromium.org/512923004

git-svn-id: svn://svn.chromium.org/blink/trunk@181004 bbb929c8-8fbe-4397-9dbb-9b2b20218538