Do not return a homepage URL for shared modules

Do not return a homepage URL for shared modules

This keeps the "Visit Website" link from showing up in chrome://extensions,
which makes sense because shared modules are automatically installed.

BUG=408927
Committed: https://crrev.com/58dac2245f1a7076bb46f9ad6b409397b7b3cb27
Cr-Commit-Position: refs/heads/master@{#293203}

[elijahtaylor1, 2014-09-02 23:31:34]

elijahtaylor@chromium.org changed reviewers:
+ miket@chromium.org

[miket_OOO, 2014-09-03 18:01:15]

lgtm

[elijahtaylor1, 2014-09-03 18:23:57]

The CQ bit was checked by elijahtaylor@chromium.org

[commit-bot: I haz the power, 2014-09-03 18:26:06]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/elijahtaylor@chromium.org/532973002/1

[commit-bot: I haz the power, 2014-09-03 21:46:34]

Committed patchset #1 (id:1) as 67a20c2f45e2ab13dc33cef63e8881dfabaaf11a

[commit-bot: I haz the power, 2014-09-10 03:28:00]

Patchset 1 (id:??) landed as
https://crrev.com/58dac2245f1a7076bb46f9ad6b409397b7b3cb27
Cr-Commit-Position: refs/heads/master@{#293203}