ui: More work to make Linux 'gn check' clean.

ui: More work to make Linux 'gn check' clean.

Tested on Linux with the following command lines:

$ gn gen out-gn
$ gn check out-gn //ui/*

More work is needed to get this enabled on .gn.

BUG=367595, 376000
TEST=see above
R=sky@chromium.org

Committed: https://crrev.com/eb2372fa7b9fbda937446996fbfc421ab46e9904
Cr-Commit-Position: refs/heads/master@{#319895}

[tfarina, 2015-03-10 01:15:02]

PTAL!

[sky, 2015-03-10 15:56:54]

LGTM

[tfarina, 2015-03-10 16:04:35]

The CQ bit was checked by tfarina@chromium.org

[commit-bot: I haz the power, 2015-03-10 16:04:52]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/988463003/1

[commit-bot: I haz the power, 2015-03-10 16:08:08]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-03-10 16:09:06]

Patchset 1 (id:??) landed as
https://crrev.com/eb2372fa7b9fbda937446996fbfc421ab46e9904
Cr-Commit-Position: refs/heads/master@{#319895}