[omnibox] Updates to handling of trivial subdomains.

1. Revert the change where we decided to ignore eTLDs
(https://crrev.com/c/644491). We figured that none of these would allow
"www" or "m" as a subdomain but the m.tumblr.com case proves this
wrong.
2. Only strip leading trivial subdomains.

Bug: 881694
Change-Id: Ia8b7bb02611edc4d6c6c2c634f428dee0bff11e2
Reviewed-on: https://chromium-review.googlesource.com/1215420
Reviewed-by: Tommy Li <tommycli@chromium.org>
Reviewed-by: Justin Donnelly <jdonnelly@chromium.org>
Reviewed-by: Carlos IL <carlosil@chromium.org>
Commit-Queue: Tommy Li <tommycli@chromium.org>
Cr-Commit-Position: refs/heads/master@{#589985}
2 files changed