Return Drive mount point by getMountPoints.

Return Drive mount point by getMountPoints.

By this CL, fileBrowserPrivate.getMountPoints starts to return Drive
(if mounted). This is the preparation for getting rid of rootList in
DocumentModel.

BUG=279276
TEST=Ran unit_tests and tested manually.

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=223614

[hidehiko, 2013-09-13 03:31:04]

This is based on 23477070 and 23983032, which are LGTM'ed.

Thank you for your review in advance,
- hidehiko

[kinaba, 2013-09-13 05:00:53]

lgtm

[commit-bot: I haz the power, 2013-09-13 11:57:50]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/hidehiko@chromium.org/23541009/1

[commit-bot: I haz the power, 2013-09-13 14:56:45]

Retried try job too often on linux_chromeos for step(s) browser_tests
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=linux_chro...

[hidehiko, 2013-09-17 11:33:43]

It turned out that I needed to fix a browser test.
Tomasz, could you kindly review the test code?

Thanks,
- hidehiko

[mtomasz, 2013-09-17 11:35:50]

lgtm for the test

[commit-bot: I haz the power, 2013-09-17 12:05:14]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/hidehiko@chromium.org/23541009/25001

[commit-bot: I haz the power, 2013-09-17 14:46:51]

Change committed as 223614