Revert of [fsp] Enable the File System Provider API for extensions.

Revert of [fsp] Enable the File System Provider API for extensions. (patchset #2 id:20001 of https://codereview.chromium.org/527663002/)

Reason for revert:
Speculative revert, failed ChromiumOS browser_tests.

[1422/1422] FileSystemProviderApiTest.Extension (11555 ms)
1 test failed:
    FileSystemProviderApiTest.Extension

http://build.chromium.org/p/chromium.chromiumos/builders/Linux%20ChromiumOS%20Tests%20%28dbg%29%282%29/builds/11812


Original issue's description:
> [fsp] Enable the File System Provider API for extensions.
> 
> Previously, only apps were allowed to use this api, however most clients will
> be actually written as extensions.
> 
> TEST=browser_tests: *FileSystemProvider*Extension*
> BUG=409487
> 
> Committed: https://chromium.googlesource.com/chromium/src/+/4acb869459901c6fa627473bb15b8a0f6190cc11

TBR=benwells@chromium.org,kalman@chromium.org,mtomasz@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=409487
Committed: https://crrev.com/be173095fb2c38f914422473535df9b2da136bb2
Cr-Commit-Position: refs/heads/master@{#293148}

[Andre, 2014-09-03 16:19:11]

Created Revert of [fsp] Enable the File System Provider API for extensions.

[commit-bot: I haz the power, 2014-09-03 16:20:31]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/andresantoso@chromium.org/537603002/1

[commit-bot: I haz the power, 2014-09-03 16:31:01]

Committed patchset #1 (id:1) as e3fe8de2f7a2ba064f05d0942d185fd12bcfa8a9

[commit-bot: I haz the power, 2014-09-10 03:26:06]

Patchset 1 (id:??) landed as
https://crrev.com/be173095fb2c38f914422473535df9b2da136bb2
Cr-Commit-Position: refs/heads/master@{#293148}