VAVEA: Turn VAAPI encoder flag into a kill switch.

chrome/test/data/extensions/api_test/cast_streaming/destination_not_set.js

 // Copyright 2014 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.
 
 var rtpStream = chrome.cast.streaming.rtpStream;
 var tabCapture = chrome.tabCapture;
 var udpTransport = chrome.cast.streaming.udpTransport;
 var createSession = chrome.cast.streaming.session.create;
 var pass = chrome.test.callbackPass;
 
 chrome.test.runTests([
   function rtpStreamStart() {
     console.log("[TEST] rtpStreamStart");
     tabCapture.capture({audio: true, video: true},
                        pass(function(stream) {
       console.log("Got MediaStream.");
       chrome.test.assertTrue(!!stream);
       createSession(stream.getAudioTracks()[0],
                     stream.getVideoTracks()[0],
                     pass(function(stream, audioId, videoId, udpId) {
         console.log("Starting.");
         var stateMachine = new TestStateMachine(stream,
                                                 audioId,
                                                 videoId,
                                                 udpId);
         var audioParams = rtpStream.getSupportedParams(audioId)[0];
-        chrome.test.assertEq(audioParams.payload.codecName, "OPUS");
+        chrome.test.assertTrue(!!audioParams.payload.codecName);
         var expectError = function(id, message) {
           chrome.test.assertEq("Destination not set.", message);
           chrome.test.succeed();
         }
         console.log("Starting RTP stream before setting destination.");
         rtpStream.onError.addListener(expectError);
         rtpStream.start(audioId, audioParams);
       }.bind(null, stream)));
     }));
   },
 ]);