Revert of WebRTC: Use the MediaStream Recording API for the audio_quality_browsertest.

chrome/test/data/webrtc/audio_extraction.js

-/**
- * Copyright 2017 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.
- */
-
-/**
- * Aggregate target bits per second for encoding of the Audio track.
- * @private
- */
-const AUDIO_BITS_PER_SECOND = 3000000;
-
-var doneCapturing = false;
-
-/**
- * Starts the audio capturing.
- *
- * @param {Number} The duration of the capture in seconds.
- */
-function startAudioCapture(capture_duration_in_seconds, output_file) {
-  console.log('Started capturing for ' + capture_duration_in_seconds + 's to '
-      + output_file);
-  var inputElement = document.getElementById('remote-view');
-
-  // |audioBitsPerSecond| must set to a large number to throw as little
-  // information away as possible.
-  var mediaRecorderOptions = {
-    audioBitsPerSecond: AUDIO_BITS_PER_SECOND,
-    mimeType: 'audio/webm',
-  };
-  var stream = inputElement.srcObject;
-  var mediaRecorder = new MediaRecorder(stream, mediaRecorderOptions);
-
-  var audio_chunks = [];
-
-  mediaRecorder.ondataavailable = function(recording) {
-    audio_chunks.push(recording.data);
-  }
-  mediaRecorder.onstop = function() {
-    var audioBlob = new Blob(audio_chunks, {type: 'audio/webm'});
-
-    var url = window.URL.createObjectURL(audioBlob);
-    var a = document.createElement('a');
-    document.body.appendChild(a);
-
-    a.href = url;
-    a.download = output_file;
-    a.click();
-
-    doneCapturing = true;
-  }
-
-  mediaRecorder.start();
-  setTimeout(function() { mediaRecorder.stop(); },
-             capture_duration_in_seconds * 1000);
-
-  returnToTest('ok-capturing');
-}
-
-function testIsDoneCapturing() {
-  returnToTest(doneCapturing.toString());
-}