Add `privacy.network.webRTCNonProxiedUdpTransportEnabled` to extensions API

chrome/common/extensions/api/privacy.json

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 [
   {
     "namespace": "privacy",
     "description": "Use the <code>chrome.privacy</code> API to control usage of the features in Chrome that can affect a user's privacy. This API relies on the <a href='types#ChromeSetting'>ChromeSetting prototype of the type API</a> for getting and setting Chrome's configuration.",
     "properties": {
       "network": {
         "type": "object",
         "value": {},
         "description": "Settings that influence Chrome's handling of network connections in general.",
         "properties": {
           "networkPredictionEnabled": {
             "$ref": "types.ChromeSetting",
             "value": ["networkPredictionEnabled", {"type":"boolean"}],
             "description": "If enabled, Chrome attempts to speed up your web browsing experience by pre-resolving DNS entries, prerendering sites (<code>&lt;link rel='prefetch' ...&gt;</code>), and preemptively opening TCP and SSL connections to servers.  This preference's value is a boolean, defaulting to <code>true</code>."
           },
           "webRTCMultipleRoutesEnabled": {
             "$ref": "types.ChromeSetting",
             "value": ["webRTCMultipleRoutesEnabled", {"type":"boolean"}],
             "description": "If enabled, Chrome will explore all possible routing options when using WebRTC to find the most performant path, possibly exposing user's private IP address. Otherwise, WebRTC traffic will be routed the same way as regular HTTP. This preference's value is a boolean, defaulting to <code>true</code>."
+          },
+          "webRTCNonProxiedUdpTransportEnabled": {
+            "$ref": "types.ChromeSetting",
+            "value": ["webRTCNonProxiedUdpTransportEnabled", {"type":"boolean"}],
+            "description": "If enabled, Chrome will use non-proxied UDP transport to connect to peers or TURN servers when using WebRTC. Since most proxy servers don't handle UDP, using UDP possibly exposes user's IP address. Turning this off force WebRTC to only use TCP. This preference's value is a boolean, defaulting to <code>true</code>."

[juberti, 2015/08/28 17:27:19]

Should mention that this will hurt performance and increase load on the proxy.

[guoweis_left_chromium, 2015/08/28 17:32:26]

Done.

           }
         }
       },
       "services": {
         "type": "object",
         "value": {},
         "description": "Settings that enable or disable features that require third-party network services provided by Google and your default search provider.",
         "properties": {
           "alternateErrorPagesEnabled": {
             "$ref": "types.ChromeSetting",
@@ skipping 66 matching lines @@
             "$ref": "types.ChromeSetting",
             "value": ["protectedContentEnabled", {"type":"boolean"}],
             "description": "<strong>Available on Windows and ChromeOS only</strong>: If enabled, Chrome provides a unique ID to plugins in order to run protected content. The value of this preference is of type boolean, and the default value is <code>true</code>.",
             "platforms": ["windows", "cros", "cros touch"]
           }
         }
       }
     }
   }
 ]