[fsp] Enable the File System Provider API on the dev channel.

[fsp] Enable the File System Provider API on the dev channel.

The read-only version is pretty much done, so we should let developers use it
on the dev channel for initial feedback.

TEST=browser_tests: *FileSystemProvider*
BUG=248427
Committed: https://crrev.com/cda0fd0081a30ddae388d95c297e3902a6c250bf
Cr-Commit-Position: refs/heads/master@{#293063}

[mtomasz, 2014-09-01 02:21:50]

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

[mtomasz, 2014-09-01 02:22:03]

@benwells: PTAL. Thanks.

[benwells, 2014-09-03 01:01:21]

lgtm

[mtomasz, 2014-09-03 03:08:59]

The CQ bit was checked by mtomasz@chromium.org

[commit-bot: I haz the power, 2014-09-03 03:09:31]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/mtomasz@chromium.org/531463002/1

[commit-bot: I haz the power, 2014-09-03 04:34:28]

Committed patchset #1 (id:1) as f8daca319a4fdfbf6c069a8623e3c12ebbb0dedb

[commit-bot: I haz the power, 2014-09-10 03:23:18]

Patchset 1 (id:??) landed as
https://crrev.com/cda0fd0081a30ddae388d95c297e3902a6c250bf
Cr-Commit-Position: refs/heads/master@{#293063}