Create a private API for controlling WebRTC's AEC3

chrome/browser/resources/hangout_services/thunk.js

Index: chrome/browser/resources/hangout_services/thunk.js
diff --git a/chrome/browser/resources/hangout_services/thunk.js b/chrome/browser/resources/hangout_services/thunk.js
index 68c28bf7dc51a5a1b8a4983c1516ba7e0bb889ca..2278a65d129a8afcd13db67edb37909e53018095 100644
--- a/chrome/browser/resources/hangout_services/thunk.js
+++ b/chrome/browser/resources/hangout_services/thunk.js
@@ -202,6 +202,12 @@ chrome.runtime.onMessageExternal.addListener(
           chrome.webrtcLoggingPrivate.stopWebRtcEventLogging(
               requestInfo, origin, doSendResponse);
           return true;
+        } else if (method == 'setAudioExperiments') {
+          var experiments = message['experiments'];
+          chrome.webrtcAudioPrivate.setAudioExperiments(
+              requestInfo, origin, experiments);
+          doSendResponse();
+          return false;
         }
 
         throw new Error('Unknown method: ' + method);