Rename "file_system_provider" to "file_system_provider_capabilities".

Rename "file_system_provider" to "file_system_provider_capabilities".

This CL renames the section in the manifest, so it's more meaningful.

TEST=Refactoring only.
BUG=474146
Committed: https://crrev.com/aa0c3c9c6ac682fccf19ef494e3f8a7f642807bc
Cr-Commit-Position: refs/heads/master@{#329316}

[mtomasz, 2015-05-11 02:22:44]

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

[mtomasz, 2015-05-11 02:24:06]

@kalman: PTAL. It's a little verbose, but I much better than previous
"file_system_provider" which could be confused with the fileSystemProvider
permission.

I was considering a shorter "provider_capabilities", but it's ambiguous as there
is a chrome.printerProvider API too.

[not at google - send to devlin, 2015-05-11 17:59:56]

lgtm

[mtomasz, 2015-05-12 00:24:56]

The CQ bit was checked by mtomasz@chromium.org

[mtomasz, 2015-05-12 00:24:57]

The patchset sent to the CQ was uploaded after l-g-t-m from kalman@chromium.org
Link to the patchset: https://codereview.chromium.org/1137813003/#ps20001
(title: "Updated tests.")

[commit-bot: I haz the power, 2015-05-12 00:26:42]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1137813003/20001

[commit-bot: I haz the power, 2015-05-12 02:11:05]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-05-12 02:12:55]

Patchset 2 (id:??) landed as
https://crrev.com/aa0c3c9c6ac682fccf19ef494e3f8a7f642807bc
Cr-Commit-Position: refs/heads/master@{#329316}