Shadow DOM became un prefixed in Chrome 35

According to chromestatus (http://www.chromestatus.com/features/4507242028072960) Shadow DOM will be turned on by default and will be unprefixed (but currently in Canary it seems to require --enable-experimental-web-platform-features --js-flags=--harmony).

Tracking issue: https://code.google.com/p/chromium/issues/detail?id=336121
Merge pull request #457 from tamersaadeh/patch-1

Shadow DOM became un prefixed in Chrome 35