libchromeos-ui: Fix linting errors.

BUG=None
TEST=unittests.
TEST=`cros lint chromeos/ui/*` reports no header guards errors.

Change-Id: I079af64a0455eb29a199a0d8112ba3a7f5965479
Reviewed-on: https://chromium-review.googlesource.com/296997
Commit-Ready: Bertrand Simonnet <bsimonnet@chromium.org>
Tested-by: Bertrand Simonnet <bsimonnet@chromium.org>
Reviewed-by: Dan Erat <derat@chromium.org>
4 files changed