Check for both use_ozone and is_chromeos for test.

The display_services_unittest relies on some Chrome OS specific code.
Add appropriate checks so the FYI bot Ozone Linux doesn't fail on it.

BUG=none

Review-Url: https://codereview.chromium.org/2476663002
Cr-Commit-Position: refs/heads/master@{#430179}
2 files changed