Additional LayoutTests to verify isolated world CSP behavior.

There are some corner cases with isolated worlds where scripts that are loaded
from an isolated world have the CSP of the page (not the isolated world) applied
to them. Whether or not we want those corner cases to remain in the long term,
these are tests that verify their behavior for now.

Review URL: https://codereview.chromium.org/340503004

git-svn-id: svn://svn.chromium.org/blink/trunk@176647 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove an unneccessary FIXME comment for HTMLToken

NOTRY=true

Review URL: https://codereview.chromium.org/342933003

git-svn-id: svn://svn.chromium.org/blink/trunk@176648 bbb929c8-8fbe-4397-9dbb-9b2b20218538