Reland: Add button to add new FSP services to Files app.

Reland: Add button to add new FSP services to Files app.

This CL adds a FSP suggest dialog which can be shown by clicking the button at
the end of the left nav.

TBR=hirono@chromium.org
TEST=Tested manually by clicking on the new button in the left nav.
BUG=471722
Committed: https://crrev.com/c1c15b3bd8fd1fa749e5544d8a167079290a9d49
Cr-Commit-Position: refs/heads/master@{#323577}

[mtomasz, 2015-04-02 23:26:54]

mtomasz@chromium.org changed reviewers:
+ hirono@chromium.org

[mtomasz, 2015-04-02 23:27:21]

Already l g t m'ed by @hirono at crbug.com/1056433003.

[mtomasz, 2015-04-02 23:27:25]

The CQ bit was checked by mtomasz@chromium.org

[commit-bot: I haz the power, 2015-04-03 00:55:00]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1052383002/1

[mtomasz, 2015-04-03 02:12:57]

Committed patchset #1 (id:1) manually as
c1c15b3bd8fd1fa749e5544d8a167079290a9d49 (presubmit successful).

[commit-bot: I haz the power, 2015-04-03 20:29:47]

Patchset 1 (id:??) landed as
https://crrev.com/c1c15b3bd8fd1fa749e5544d8a167079290a9d49
Cr-Commit-Position: refs/heads/master@{#323577}