Do not block painting for in-body CSS
This mirrors the Firefox behavior where in-body stylesheets
are not render-blocking. Developers can force the parser to
block and get Edge/IE behavior by inserting script tags after
the stylesheets (they will need to anyway because of Firefox).
BUG=
481122
Committed:
https://crrev.com/ef8540e50d8f1e1cbd8b403b393a90d29985b9c5
Cr-Commit-Position: refs/heads/master@{#393347}