Remove OmahaClient low-end device check.

Existing users who have updated Chrome will not be forced to
change to the accessibility tab switcher. New users to update
from a chrome version before svelte mode to a version after
svelte mode was introduced will get switched to the
accessibility tab switcher.

This change saves ~45ms for every device (measured on N5 so it
should save more on slower devices). The accessibility tab
switcher is much faster and should prove to be a better
experience on low-end devices.

BUG=473352

Review URL: https://codereview.chromium.org/1266073002

Cr-Commit-Position: refs/heads/master@{#341194}
2 files changed