Navi A11y - Focus Heading in each step of onboarding for screen readers.

Bug: 920685
Change-Id: Ibbb068b85f5bd3a94b5823dbece9409ea68bcb36
Reviewed-on: https://chromium-review.googlesource.com/c/1406180
Commit-Queue: Hector Carmona <hcarmona@chromium.org>
Reviewed-by: Dan Beam <dbeam@chromium.org>
Cr-Commit-Position: refs/heads/master@{#622118}
8 files changed