Convert GN visibility to be a list.

Convert GN visibility to be a list.

GN visibility currently allows either string or list types, but this is causing
some problems for some templates. I'm going to require it to be lists, so am
changing all callers before pushing the new binary.

R=jochen@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=23789

[brettw, 2014-09-08 20:35:55]

brettw@chromium.org changed reviewers:
+ jochen@chromium.org

[jochen (gone - plz use gerrit), 2014-09-09 07:50:51]

lgtm

[jochen (gone - plz use gerrit), 2014-09-09 08:57:37]

Committed patchset #1 (id:1) manually as 23789 (presubmit successful).