[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-Original-Commit-Position: refs/heads/master@{#589985}(cherry picked from commit 1883bad43889c9f0a5d7f6ca3dabff648c73bb90)
Reviewed-on: https://chromium-review.googlesource.com/1216815
Cr-Commit-Position: refs/branch-heads/3538@{#238}
Cr-Branched-From: 79f7c91a2b2a2932cd447fa6f865cb6662fa8fa6-refs/heads/master@{#587811}
2 files changed