Close new child window if its only navigation was opening a Native app.

Close new child window if its only navigation was opening a Native app.

There is no reason to keep a bank Tab in case if newly opened window
launched an external app. This behavior is similar to launching native
apps.

BUG=496419
Committed: https://crrev.com/af891d356a02e245e7be1aa7ac6c881cf92433a3
Cr-Commit-Position: refs/heads/master@{#333120}

[Eugene But (OOO till 7-30), 2015-06-04 01:35:10]

eugenebut@chromium.org changed reviewers:
+ jyquinn@chromium.org, stuartmorgan@chromium.org

[Jackie Quinn, 2015-06-04 02:15:14]

lgtm!

[stuartmorgan, 2015-06-05 15:18:24]

lgtm

[Eugene But (OOO till 7-30), 2015-06-05 20:28:44]

The CQ bit was checked by eugenebut@chromium.org

[commit-bot: I haz the power, 2015-06-05 20:30:30]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1146133005/1

[commit-bot: I haz the power, 2015-06-05 20:43:29]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-06-05 20:44:23]

Patchset 1 (id:??) landed as
https://crrev.com/af891d356a02e245e7be1aa7ac6c881cf92433a3
Cr-Commit-Position: refs/heads/master@{#333120}