Don't fire error messages if an install kills Chrome

Don't fire error messages if an install kills Chrome

Die silently if the Play Store starts installing an app
promoted by the webpage and Chrome dies in the background
before returning.  In this case, the infobar will disappear
before the user gets back anyway.

BUG=453170
Committed: https://crrev.com/11c081ff9dcf24b3fd9a530af0ea2badf013c6c6
Cr-Commit-Position: refs/heads/master@{#315406}

[gone, 2015-02-09 19:52:24]

dfalcantara@chromium.org changed reviewers:
+ dtrainor@chromium.org

[David Trainor- moved to gerrit, 2015-02-09 21:24:13]

lgtm

[gone, 2015-02-09 21:36:19]

The CQ bit was checked by dfalcantara@chromium.org

[commit-bot: I haz the power, 2015-02-09 21:37:34]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/913593002/1

[commit-bot: I haz the power, 2015-02-09 22:15:30]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-02-09 22:16:16]

Patchset 1 (id:??) landed as
https://crrev.com/11c081ff9dcf24b3fd9a530af0ea2badf013c6c6
Cr-Commit-Position: refs/heads/master@{#315406}