Restrict the File System Provier API permission to Chrome OS only.

Restrict the File System Provier API permission to Chrome OS only.

This API implementation is compiled on Chrome OS only, so the permission should
be available on Chrome OS only.

TEST=Tested manually that still works on Chrome OS.
BUG=248427
Committed: https://crrev.com/bbe7526503cbf1fc019d4e2c5eea8bf661588f52
Cr-Commit-Position: refs/heads/master@{#295918}

[mtomasz, 2014-09-19 02:11:16]

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

[mtomasz, 2014-09-19 02:11:34]

@miket: PTAL. Thanks!

[miket_OOO, 2014-09-19 19:04:39]

On 2014/09/19 02:11:34, mtomasz wrote:
> @miket: PTAL. Thanks!

Do the docs reflect this limited availability? They should -- even if it's a
temporary situation. Otherwise LGTM.

[mtomasz, 2014-09-20 00:35:58]

On 2014/09/19 19:04:39, miket wrote:
> On 2014/09/19 02:11:34, mtomasz wrote:
> > @miket: PTAL. Thanks!
> 
> Do the docs reflect this limited availability? They should -- even if it's a
> temporary situation. Otherwise LGTM.

I think the warning should be automatically generated. I'll check it before
committing.

[mtomasz, 2014-09-22 01:16:29]

On 2014/09/20 00:35:58, mtomasz wrote:
> On 2014/09/19 19:04:39, miket wrote:
> > On 2014/09/19 02:11:34, mtomasz wrote:
> > > @miket: PTAL. Thanks!
> > 
> > Do the docs reflect this limited availability? They should -- even if it's a
> > temporary situation. Otherwise LGTM.
> 
> I think the warning should be automatically generated. I'll check it before
> committing.

Added a notice same as for fileBrowserHandler.

[mtomasz, 2014-09-22 01:16:34]

The CQ bit was checked by mtomasz@chromium.org

[commit-bot: I haz the power, 2014-09-22 01:17:02]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/581303002/20001

[commit-bot: I haz the power, 2014-09-22 03:17:45]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-09-22 03:17:47]

Exceeded time limit waiting for builds to trigger.

[mtomasz, 2014-09-22 03:18:27]

The CQ bit was checked by mtomasz@chromium.org

[commit-bot: I haz the power, 2014-09-22 03:19:36]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/581303002/20001

[commit-bot: I haz the power, 2014-09-22 03:50:12]

Committed patchset #2 (id:20001) as 3c8bd874795b993fec3dbf99bbf05a7c7bae1fcc

[commit-bot: I haz the power, 2014-09-22 03:50:49]

Patchset 2 (id:??) landed as
https://crrev.com/bbe7526503cbf1fc019d4e2c5eea8bf661588f52
Cr-Commit-Position: refs/heads/master@{#295918}