chromium: Merge pull request #9112 from @benley.

Addresses problems loading the WideVine plugin.

I can't actually test it by myself, but I'm merging this because
according to issue #8479, WideVine currently isn't working on Nix(OS),
so we can't get worse than that.

Thanks a whole lot to @benley, I probably would have spent hours or even
days to debug this nasty typo.