Revert of Add WebRuntimeFeatures::enablePermissionsAPI.

Revert of Add WebRuntimeFeatures::enablePermissionsAPI. (patchset #1 id:1 of https://codereview.chromium.org/1156113007/)

Reason for revert:
This change has been applied twice, and is causing compile failures on the following bots (and probably more):

http://build.chromium.org/p/chromium.webkit/builders/WebKit%20Win%20Builder/builds/81064
http://build.chromium.org/p/chromium.webkit/builders/WebKit%20Win%20Builder%20%28dbg%29/builds/73845
http://build.chromium.org/p/chromium.webkit/builders/Linux%20GN/builds/32401

Was this supposed to land on a different branch?

Original issue's description:
> Add WebRuntimeFeatures::enablePermissionsAPI.
> 
> Add the ability to control whether we want to expose the Permissions API
> in blink at runtime. This is e.g. needed for WebView where the
> Permissions API is currently not supported.
> 
> BUG=489926
> TBR=dglazkov
> NOTRY=true
> 
> Review URL: https://codereview.chromium.org/1150653002
> 
> git-svn-id: svn://svn.chromium.org/blink/trunk@195691 bbb929c8-8fbe-4397-9dbb-9b2b20218538
> (cherry picked from commit 867b90077485d07fc4dc60de24112bdad2085e6a)
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=195998

TBR=timvolodine@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=489926
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=195999

[samuong, 2015-05-27 18:35:10]

Created Revert of Add WebRuntimeFeatures::enablePermissionsAPI.

[commit-bot: I haz the power, 2015-05-27 18:36:14]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1157773005/1

[commit-bot: I haz the power, 2015-05-27 18:37:13]

Committed patchset #1 (id:1) as
https://src.chromium.org/viewvc/blink?view=rev&revision=195999