This reverts most of commit 2d842f1425,
leaving only the test added in it, and reimplements the same
functionality better.
Instead of stripping /*@noflip*/ annotations in CSSJanus, which is
incompatible with other implementations that preserve it, extend
CSSMin to allow other CSS comments to be present before the
rule-global @embed annotation. (This required making the regex logic
in it even worse than it was, but it's actually slightly less terrible
than I expected it would be. Good thing we have tests!)
Bug: 69698
Change-Id: I58603ef64f7d7cdc6461b34721a4d6b15f15ad79
4c01f8b2bc