Dynamically inserted stylesheets no longer block rendering in Chrome

Chrome would stop parsing HTML when downloading programmatically injected CSS before. But according to the HTML5 spec, the injected CSS should not be blocking.

The patch will soon to be shipped as it has included from chromium 50.0.2628.0. and release date of Chrome 50 expected to 19 April, 2016.

https://codereview.chromium.org/1603873004
https://code.google.com/p/chromium/issues/detail?id=571725
https://groups.google.com/a/chromium.org/forum/#!msg/blink-dev/xvxa1WaFuFc/I3Pd9HRIBQAJ