Remove Chrome OS-only sources only if the OS is Chrome OS.

If the OS is not Chrome OS, those sources are automatically removed
because their file pathnames contain "chromeos". So we can't remove
them from 'sources' again -- GN treats that as an error.

Re-enable the Chrome OS input method tests for use_ozone because
bug 362698 has been fixed.

R=kpschoedel@chromium.org,sky@chromium.org
BUG=354036,362698

Review URL: https://codereview.chromium.org/1003853005

Cr-Commit-Position: refs/heads/master@{#320596}
3 files changed