Redirects off-origin navigations in an installed PWAs to a CustomTab.

This is done in order to improve UX by getting rid of a "minibar" toolbar
(to be done in a follow-up patch) and bring more app-like feel to PWAs.

In a long run this will help bring implementation of Minimal-UI, which requires
replacing "minibar" with a new "minimal-ui" toolbar.

BUG=709889

Review-Url: https://codereview.chromium.org/2829943002
Cr-Commit-Position: refs/heads/master@{#474625}
14 files changed