Add m-esr52 at 52.6.0

1 files changed, 970 insertions, 0 deletions

diff --git a/dom/media/tests/mochitest/head.js b/dom/media/tests/mochitest/head.js
new file mode 100644
index 000000000..e4d86c750
--- /dev/null
+++ b/dom/media/tests/mochitest/head.js
@@ -0,0 +1,970 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+var Cc = SpecialPowers.Cc;
+var Ci = SpecialPowers.Ci;
+
+// Specifies whether we are using fake streams to run this automation
+var FAKE_ENABLED = true;
+var TEST_AUDIO_FREQ = 1000;
+try {
+  var audioDevice = SpecialPowers.getCharPref('media.audio_loopback_dev');
+  var videoDevice = SpecialPowers.getCharPref('media.video_loopback_dev');
+  dump('TEST DEVICES: Using media devices:\n');
+  dump('audio: ' + audioDevice + '\nvideo: ' + videoDevice + '\n');
+  FAKE_ENABLED = false;
+  TEST_AUDIO_FREQ = 440;
+} catch (e) {
+  dump('TEST DEVICES: No test devices found (in media.{audio,video}_loopback_dev, using fake streams.\n');
+  FAKE_ENABLED = true;
+}
+
+/**
+ * This class provides helpers around analysing the audio content in a stream
+ * using WebAudio AnalyserNodes.
+ *
+ * @constructor
+ * @param {object} stream
+ *                 A MediaStream object whose audio track we shall analyse.
+ */
+function AudioStreamAnalyser(ac, stream) {
+  this.audioContext = ac;
+  this.stream = stream;
+  this.sourceNodes = [];
+  this.analyser = this.audioContext.createAnalyser();
+  // Setting values lower than default for speedier testing on emulators
+  this.analyser.smoothingTimeConstant = 0.2;
+  this.analyser.fftSize = 1024;
+  this.connectTrack = t => {
+    let source = this.audioContext.createMediaStreamSource(new MediaStream([t]));
+    this.sourceNodes.push(source);
+    source.connect(this.analyser);
+  };
+  this.stream.getAudioTracks().forEach(t => this.connectTrack(t));
+  this.onaddtrack = ev => this.connectTrack(ev.track);
+  this.stream.addEventListener("addtrack", this.onaddtrack);
+  this.data = new Uint8Array(this.analyser.frequencyBinCount);
+}
+
+AudioStreamAnalyser.prototype = {
+  /**
+   * Get an array of frequency domain data for our stream's audio track.
+   *
+   * @returns {array} A Uint8Array containing the frequency domain data.
+   */
+  getByteFrequencyData: function() {
+    this.analyser.getByteFrequencyData(this.data);
+    return this.data;
+  },
+
+  /**
+   * Append a canvas to the DOM where the frequency data are drawn.
+   * Useful to debug tests.
+   */
+  enableDebugCanvas: function() {
+    var cvs = this.debugCanvas = document.createElement("canvas");
+    const content = document.getElementById("content");
+    content.insertBefore(cvs, content.children[0]);
+
+    // Easy: 1px per bin
+    cvs.width = this.analyser.frequencyBinCount;
+    cvs.height = 128;
+    cvs.style.border = "1px solid red";
+
+    var c = cvs.getContext('2d');
+    c.fillStyle = 'black';
+
+    var self = this;
+    function render() {
+      c.clearRect(0, 0, cvs.width, cvs.height);
+      var array = self.getByteFrequencyData();
+      for (var i = 0; i < array.length; i++) {
+        c.fillRect(i, (cvs.height - (array[i] / 2)), 1, cvs.height);
+      }
+      if (!cvs.stopDrawing) {
+        requestAnimationFrame(render);
+      }
+    }
+    requestAnimationFrame(render);
+  },
+
+  /**
+   * Stop drawing of and remove the debug canvas from the DOM if it was
+   * previously added.
+   */
+  disableDebugCanvas: function() {
+    if (!this.debugCanvas || !this.debugCanvas.parentElement) {
+      return;
+    }
+
+    this.debugCanvas.stopDrawing = true;
+    this.debugCanvas.parentElement.removeChild(this.debugCanvas);
+  },
+
+  /**
+   * Disconnects the input stream from our internal analyser node.
+   * Call this to reduce main thread processing, mostly necessary on slow
+   * devices.
+   */
+  disconnect: function() {
+    this.disableDebugCanvas();
+    this.sourceNodes.forEach(n => n.disconnect());
+    this.sourceNodes = [];
+    this.stream.removeEventListener("addtrack", this.onaddtrack);
+  },
+
+  /**
+   * Return a Promise, that will be resolved when the function passed as
+   * argument, when called, returns true (meaning the analysis was a
+   * success).
+   *
+   * @param {function} analysisFunction
+   *        A fonction that performs an analysis, and returns true if the
+   *        analysis was a success (i.e. it found what it was looking for)
+   */
+  waitForAnalysisSuccess: function(analysisFunction) {
+    var self = this;
+    return new Promise((resolve, reject) => {
+      function analysisLoop() {
+        var success = analysisFunction(self.getByteFrequencyData());
+        if (success) {
+          resolve();
+          return;
+        }
+        // else, we need more time
+        requestAnimationFrame(analysisLoop);
+      }
+      // We need to give the Analyser some time to start gathering data.
+      wait(200).then(analysisLoop);
+    });
+  },
+
+  /**
+   * Return the FFT bin index for a given frequency.
+   *
+   * @param {double} frequency
+   *        The frequency for whicht to return the bin number.
+   * @returns {integer} the index of the bin in the FFT array.
+   */
+  binIndexForFrequency: function(frequency) {
+    return 1 + Math.round(frequency *
+                          this.analyser.fftSize /
+                          this.audioContext.sampleRate);
+  },
+
+  /**
+   * Reverse operation, get the frequency for a bin index.
+   *
+   * @param {integer} index an index in an FFT array
+   * @returns {double} the frequency for this bin
+   */
+  frequencyForBinIndex: function(index) {
+    return (index - 1) *
+           this.audioContext.sampleRate /
+           this.analyser.fftSize;
+  }
+};
+
+/**
+ * Creates a MediaStream with an audio track containing a sine tone at the
+ * given frequency.
+ *
+ * @param {AudioContext} ac
+ *        AudioContext in which to create the OscillatorNode backing the stream
+ * @param {double} frequency
+ *        The frequency in Hz of the generated sine tone
+ * @returns {MediaStream} the MediaStream containing sine tone audio track
+ */
+function createOscillatorStream(ac, frequency) {
+  var osc = ac.createOscillator();
+  osc.frequency.value = frequency;
+
+  var oscDest = ac.createMediaStreamDestination();
+  osc.connect(oscDest);
+  osc.start();
+  return oscDest.stream;
+}
+
+/**
+ * Create the necessary HTML elements for head and body as used by Mochitests
+ *
+ * @param {object} meta
+ *        Meta information of the test
+ * @param {string} meta.title
+ *        Description of the test
+ * @param {string} [meta.bug]
+ *        Bug the test was created for
+ * @param {boolean} [meta.visible=false]
+ *        Visibility of the media elements
+ */
+function realCreateHTML(meta) {
+  var test = document.getElementById('test');
+
+  // Create the head content
+  var elem = document.createElement('meta');
+  elem.setAttribute('charset', 'utf-8');
+  document.head.appendChild(elem);
+
+  var title = document.createElement('title');
+  title.textContent = meta.title;
+  document.head.appendChild(title);
+
+  // Create the body content
+  var anchor = document.createElement('a');
+  anchor.textContent = meta.title;
+  if (meta.bug) {
+    anchor.setAttribute('href', 'https://bugzilla.mozilla.org/show_bug.cgi?id=' + meta.bug);
+  } else {
+    anchor.setAttribute('target', '_blank');
+  }
+
+  document.body.insertBefore(anchor, test);
+
+  var display = document.createElement('p');
+  display.setAttribute('id', 'display');
+  document.body.insertBefore(display, test);
+
+  var content = document.createElement('div');
+  content.setAttribute('id', 'content');
+  content.style.display = meta.visible ? 'block' : "none";
+  document.body.appendChild(content);
+}
+
+/**
+ * Creates an element of the given type, assigns the given id, sets the controls
+ * and autoplay attributes and adds it to the content node.
+ *
+ * @param {string} type
+ *        Defining if we should create an "audio" or "video" element
+ * @param {string} id
+ *        A string to use as the element id.
+ */
+function createMediaElement(type, id) {
+  const element = document.createElement(type);
+  element.setAttribute('id', id);
+  element.setAttribute('height', 100);
+  element.setAttribute('width', 150);
+  element.setAttribute('controls', 'controls');
+  element.setAttribute('autoplay', 'autoplay');
+  document.getElementById('content').appendChild(element);
+
+  return element;
+}
+
+/**
+ * Returns an existing element for the given track with the given idPrefix,
+ * as it was added by createMediaElementForTrack().
+ *
+ * @param {MediaStreamTrack} track
+ *        Track used as the element's source.
+ * @param {string} idPrefix
+ *        A string to use as the element id. The track id will also be appended.
+ */
+function getMediaElementForTrack(track, idPrefix) {
+  return document.getElementById(idPrefix + '_' + track.id);
+}
+
+/**
+ * Create a media element with a track as source and attach it to the content
+ * node.
+ *
+ * @param {MediaStreamTrack} track
+ *        Track for use as source.
+ * @param {string} idPrefix
+ *        A string to use as the element id. The track id will also be appended.
+ * @return {HTMLMediaElement} The created HTML media element
+ */
+function createMediaElementForTrack(track, idPrefix) {
+  const id = idPrefix + '_' + track.id;
+  const element = createMediaElement(track.kind, id);
+  element.srcObject = new MediaStream([track]);
+
+  return element;
+}
+
+
+/**
+ * Wrapper function for mediaDevices.getUserMedia used by some tests. Whether
+ * to use fake devices or not is now determined in pref further below instead.
+ *
+ * @param {Dictionary} constraints
+ *        The constraints for this mozGetUserMedia callback
+ */
+function getUserMedia(constraints) {
+  info("Call getUserMedia for " + JSON.stringify(constraints));
+  return navigator.mediaDevices.getUserMedia(constraints)
+    .then(stream => (checkMediaStreamTracks(constraints, stream), stream));
+}
+
+// These are the promises we use to track that the prerequisites for the test
+// are in place before running it.
+var setTestOptions;
+var testConfigured = new Promise(r => setTestOptions = r);
+
+function setupEnvironment() {
+  if (!window.SimpleTest) {
+    // Running under Steeplechase
+    return;
+  }
+
+  var defaultMochitestPrefs = {
+    'set': [
+      ['media.peerconnection.enabled', true],
+      ['media.peerconnection.identity.enabled', true],
+      ['media.peerconnection.identity.timeout', 120000],
+      ['media.peerconnection.ice.stun_client_maximum_transmits', 14],
+      ['media.peerconnection.ice.trickle_grace_period', 30000],
+      ['media.navigator.permission.disabled', true],
+      ['media.navigator.streams.fake', FAKE_ENABLED],
+      ['media.getusermedia.screensharing.enabled', true],
+      ['media.getusermedia.screensharing.allowed_domains', "mochi.test"],
+      ['media.getusermedia.audiocapture.enabled', true],
+      ['media.recorder.audio_node.enabled', true]
+    ]
+  };
+
+  const isAndroid = !!navigator.userAgent.includes("Android");
+
+  if (isAndroid) {
+    defaultMochitestPrefs.set.push(
+      ["media.navigator.video.default_width", 320],
+      ["media.navigator.video.default_height", 240],
+      ["media.navigator.video.max_fr", 10],
+      ["media.autoplay.enabled", true]
+    );
+  }
+
+  // Running as a Mochitest.
+  SimpleTest.requestFlakyTimeout("WebRTC inherently depends on timeouts");
+  window.finish = () => SimpleTest.finish();
+  SpecialPowers.pushPrefEnv(defaultMochitestPrefs, setTestOptions);
+
+  // We don't care about waiting for this to complete, we just want to ensure
+  // that we don't build up a huge backlog of GC work.
+  SpecialPowers.exactGC();
+}
+
+// This is called by steeplechase; which provides the test configuration options
+// directly to the test through this function.  If we're not on steeplechase,
+// the test is configured directly and immediately.
+function run_test(is_initiator,timeout) {
+  var options = { is_local: is_initiator,
+                  is_remote: !is_initiator };
+
+  setTimeout(() => {
+    unexpectedEventArrived(new Error("PeerConnectionTest timed out after "+timeout+"s"));
+  }, timeout);
+
+  // Also load the steeplechase test code.
+  var s = document.createElement("script");
+  s.src = "/test.js";
+  s.onload = () => setTestOptions(options);
+  document.head.appendChild(s);
+}
+
+function runTestWhenReady(testFunc) {
+  setupEnvironment();
+  return testConfigured.then(options => testFunc(options))
+    .catch(e => {
+      ok(false, 'Error executing test: ' + e +
+        ((typeof e.stack === 'string') ?
+        (' ' + e.stack.split('\n').join(' ... ')) : ''));
+      SimpleTest.finish();
+    });
+}
+
+
+/**
+ * Checks that the media stream tracks have the expected amount of tracks
+ * with the correct kind and id based on the type and constraints given.
+ *
+ * @param {Object} constraints specifies whether the stream should have
+ *                             audio, video, or both
+ * @param {String} type the type of media stream tracks being checked
+ * @param {sequence<MediaStreamTrack>} mediaStreamTracks the media stream
+ *                                     tracks being checked
+ */
+function checkMediaStreamTracksByType(constraints, type, mediaStreamTracks) {
+  if (constraints[type]) {
+    is(mediaStreamTracks.length, 1, 'One ' + type + ' track shall be present');
+
+    if (mediaStreamTracks.length) {
+      is(mediaStreamTracks[0].kind, type, 'Track kind should be ' + type);
+      ok(mediaStreamTracks[0].id, 'Track id should be defined');
+    }
+  } else {
+    is(mediaStreamTracks.length, 0, 'No ' + type + ' tracks shall be present');
+  }
+}
+
+/**
+ * Check that the given media stream contains the expected media stream
+ * tracks given the associated audio & video constraints provided.
+ *
+ * @param {Object} constraints specifies whether the stream should have
+ *                             audio, video, or both
+ * @param {MediaStream} mediaStream the media stream being checked
+ */
+function checkMediaStreamTracks(constraints, mediaStream) {
+  checkMediaStreamTracksByType(constraints, 'audio',
+    mediaStream.getAudioTracks());
+  checkMediaStreamTracksByType(constraints, 'video',
+    mediaStream.getVideoTracks());
+}
+
+/**
+ * Check that a media stream contains exactly a set of media stream tracks.
+ *
+ * @param {MediaStream} mediaStream the media stream being checked
+ * @param {Array} tracks the tracks that should exist in mediaStream
+ * @param {String} [message] an optional message to pass to asserts
+ */
+function checkMediaStreamContains(mediaStream, tracks, message) {
+  message = message ? (message + ": ") : "";
+  tracks.forEach(t => ok(mediaStream.getTrackById(t.id),
+                         message + "MediaStream " + mediaStream.id +
+                         " contains track " + t.id));
+  is(mediaStream.getTracks().length, tracks.length,
+     message + "MediaStream " + mediaStream.id + " contains no extra tracks");
+}
+
+function checkMediaStreamCloneAgainstOriginal(clone, original) {
+  isnot(clone.id.length, 0, "Stream clone should have an id string");
+  isnot(clone, original,
+        "Stream clone should be different from the original");
+  isnot(clone.id, original.id,
+        "Stream clone's id should be different from the original's");
+  is(clone.getAudioTracks().length, original.getAudioTracks().length,
+     "All audio tracks should get cloned");
+  is(clone.getVideoTracks().length, original.getVideoTracks().length,
+     "All video tracks should get cloned");
+  is(clone.active, original.active,
+     "Active state should be preserved");
+  original.getTracks()
+          .forEach(t => ok(!clone.getTrackById(t.id),
+                           "The clone's tracks should be originals"));
+}
+
+function checkMediaStreamTrackCloneAgainstOriginal(clone, original) {
+  isnot(clone.id.length, 0,
+        "Track clone should have an id string");
+  isnot(clone, original,
+        "Track clone should be different from the original");
+  isnot(clone.id, original.id,
+        "Track clone's id should be different from the original's");
+  is(clone.kind, original.kind,
+     "Track clone's kind should be same as the original's");
+  is(clone.enabled, original.enabled,
+     "Track clone's kind should be same as the original's");
+  is(clone.readyState, original.readyState,
+     "Track clone's readyState should be same as the original's");
+}
+
+/*** Utility methods */
+
+/** The dreadful setTimeout, use sparingly */
+function wait(time, message) {
+  return new Promise(r => setTimeout(() => r(message), time));
+}
+
+/** The even more dreadful setInterval, use even more sparingly */
+function waitUntil(func, time) {
+  return new Promise(resolve => {
+    var interval = setInterval(() => {
+      if (func())  {
+        clearInterval(interval);
+        resolve();
+      }
+    }, time || 200);
+  });
+}
+
+/** Time out while waiting for a promise to get resolved or rejected. */
+var timeout = (promise, time, msg) =>
+  Promise.race([promise, wait(time).then(() => Promise.reject(new Error(msg)))]);
+
+/** Adds a |finally| function to a promise whose argument is invoked whether the
+ * promise is resolved or rejected, and that does not interfere with chaining.*/
+var addFinallyToPromise = promise => {
+  promise.finally = func => {
+    return promise.then(
+      result => {
+        func();
+        return Promise.resolve(result);
+      },
+      error => {
+        func();
+        return Promise.reject(error);
+      }
+    );
+  }
+  return promise;
+}
+
+/** Use event listener to call passed-in function on fire until it returns true */
+var listenUntil = (target, eventName, onFire) => {
+  return new Promise(resolve => target.addEventListener(eventName,
+                                                        function callback(event) {
+    var result = onFire(event);
+    if (result) {
+      target.removeEventListener(eventName, callback, false);
+      resolve(result);
+    }
+  }, false));
+};
+
+/* Test that a function throws the right error */
+function mustThrowWith(msg, reason, f) {
+  try {
+    f();
+    ok(false, msg + " must throw");
+  } catch (e) {
+    is(e.name, reason, msg + " must throw: " + e.message);
+  }
+};
+
+
+/*** Test control flow methods */
+
+/**
+ * Generates a callback function fired only under unexpected circumstances
+ * while running the tests. The generated function kills off the test as well
+ * gracefully.
+ *
+ * @param {String} [message]
+ *        An optional message to show if no object gets passed into the
+ *        generated callback method.
+ */
+function generateErrorCallback(message) {
+  var stack = new Error().stack.split("\n");
+  stack.shift(); // Don't include this instantiation frame
+
+  /**
+   * @param {object} aObj
+   *        The object fired back from the callback
+   */
+  return aObj => {
+    if (aObj) {
+      if (aObj.name && aObj.message) {
+        ok(false, "Unexpected callback for '" + aObj.name +
+           "' with message = '" + aObj.message + "' at " +
+           JSON.stringify(stack));
+      } else {
+        ok(false, "Unexpected callback with = '" + aObj +
+           "' at: " + JSON.stringify(stack));
+      }
+    } else {
+      ok(false, "Unexpected callback with message = '" + message +
+         "' at: " + JSON.stringify(stack));
+    }
+    throw new Error("Unexpected callback");
+  }
+}
+
+var unexpectedEventArrived;
+var rejectOnUnexpectedEvent = new Promise((x, reject) => {
+  unexpectedEventArrived = reject;
+});
+
+/**
+ * Generates a callback function fired only for unexpected events happening.
+ *
+ * @param {String} description
+          Description of the object for which the event has been fired
+ * @param {String} eventName
+          Name of the unexpected event
+ */
+function unexpectedEvent(message, eventName) {
+  var stack = new Error().stack.split("\n");
+  stack.shift(); // Don't include this instantiation frame
+
+  return e => {
+    var details = "Unexpected event '" + eventName + "' fired with message = '" +
+        message + "' at: " + JSON.stringify(stack);
+    ok(false, details);
+    unexpectedEventArrived(new Error(details));
+  }
+}
+
+/**
+ * Implements the one-shot event pattern used throughout.  Each of the 'onxxx'
+ * attributes on the wrappers can be set with a custom handler.  Prior to the
+ * handler being set, if the event fires, it causes the test execution to halt.
+ * That handler is used exactly once, after which the original, error-generating
+ * handler is re-installed.  Thus, each event handler is used at most once.
+ *
+ * @param {object} wrapper
+ *        The wrapper on which the psuedo-handler is installed
+ * @param {object} obj
+ *        The real source of events
+ * @param {string} event
+ *        The name of the event
+ */
+function createOneShotEventWrapper(wrapper, obj, event) {
+  var onx = 'on' + event;
+  var unexpected = unexpectedEvent(wrapper, event);
+  wrapper[onx] = unexpected;
+  obj[onx] = e => {
+    info(wrapper + ': "on' + event + '" event fired');
+    e.wrapper = wrapper;
+    wrapper[onx](e);
+    wrapper[onx] = unexpected;
+  };
+}
+
+/**
+ * Returns a promise that resolves when `target` has raised an event with the
+ * given name the given number of times. Cancel the returned promise by passing
+ * in a `cancelPromise` and resolve it.
+ *
+ * @param {object} target
+ *        The target on which the event should occur.
+ * @param {string} name
+ *        The name of the event that should occur.
+ * @param {integer} count
+ *        Optional number of times the event should be raised before resolving.
+ * @param {promise} cancelPromise
+ *        Optional promise that on resolving rejects the returned promise,
+ *        so we can avoid logging results after a test has finished.
+ * @returns {promise} A promise that resolves to the last of the seen events.
+ */
+function haveEvents(target, name, count, cancelPromise) {
+  var listener;
+  var counter = count || 1;
+  return Promise.race([
+    (cancelPromise || new Promise(() => {})).then(e => Promise.reject(e)),
+    new Promise(resolve =>
+        target.addEventListener(name, listener = e => (--counter < 1 && resolve(e))))
+  ])
+  .then(e => (target.removeEventListener(name, listener), e));
+};
+
+/**
+ * Returns a promise that resolves when `target` has raised an event with the
+ * given name. Cancel the returned promise by passing in a `cancelPromise` and
+ * resolve it.
+ *
+ * @param {object} target
+ *        The target on which the event should occur.
+ * @param {string} name
+ *        The name of the event that should occur.
+ * @param {promise} cancelPromise
+ *        Optional promise that on resolving rejects the returned promise,
+ *        so we can avoid logging results after a test has finished.
+ * @returns {promise} A promise that resolves to the seen event.
+ */
+function haveEvent(target, name, cancelPromise) {
+  return haveEvents(target, name, 1, cancelPromise);
+};
+
+/**
+ * Returns a promise that resolves if the target has not seen the given event
+ * after one crank (or until the given timeoutPromise resolves) of the event
+ * loop.
+ *
+ * @param {object} target
+ *        The target on which the event should not occur.
+ * @param {string} name
+ *        The name of the event that should not occur.
+ * @param {promise} timeoutPromise
+ *        Optional promise defining how long we should wait before resolving.
+ * @returns {promise} A promise that is rejected if we see the given event, or
+ *                    resolves after a timeout otherwise.
+ */
+function haveNoEvent(target, name, timeoutPromise) {
+  return haveEvent(target, name, timeoutPromise || wait(0))
+    .then(() => Promise.reject(new Error("Too many " + name + " events")),
+          () => {});
+};
+
+/**
+ * Returns a promise that resolves after the target has seen the given number
+ * of events but no such event in a following crank of the event loop.
+ *
+ * @param {object} target
+ *        The target on which the events should occur.
+ * @param {string} name
+ *        The name of the event that should occur.
+ * @param {integer} count
+ *        Optional number of times the event should be raised before resolving.
+ * @param {promise} cancelPromise
+ *        Optional promise that on resolving rejects the returned promise,
+ *        so we can avoid logging results after a test has finished.
+ * @returns {promise} A promise that resolves to the last of the seen events.
+ */
+function haveEventsButNoMore(target, name, count, cancelPromise) {
+  return haveEvents(target, name, count, cancelPromise)
+    .then(e => haveNoEvent(target, name).then(() => e));
+};
+
+/**
+ * This class executes a series of functions in a continuous sequence.
+ * Promise-bearing functions are executed after the previous promise completes.
+ *
+ * @constructor
+ * @param {object} framework
+ *        A back reference to the framework which makes use of the class. It is
+ *        passed to each command callback.
+ * @param {function[]} commandList
+ *        Commands to set during initialization
+ */
+function CommandChain(framework, commandList) {
+  this._framework = framework;
+  this.commands = commandList || [ ];
+}
+
+CommandChain.prototype = {
+  /**
+   * Start the command chain.  This returns a promise that always resolves
+   * cleanly (this catches errors and fails the test case).
+   */
+  execute: function () {
+    return this.commands.reduce((prev, next, i) => {
+      if (typeof next !== 'function' || !next.name) {
+        throw new Error('registered non-function' + next);
+      }
+
+      return prev.then(() => {
+        info('Run step ' + (i + 1) + ': ' + next.name);
+        return Promise.race([ next(this._framework), rejectOnUnexpectedEvent ]);
+      });
+    }, Promise.resolve())
+      .catch(e =>
+             ok(false, 'Error in test execution: ' + e +
+                ((typeof e.stack === 'string') ?
+                 (' ' + e.stack.split('\n').join(' ... ')) : '')));
+  },
+
+  /**
+   * Add new commands to the end of the chain
+   */
+  append: function(commands) {
+    this.commands = this.commands.concat(commands);
+  },
+
+  /**
+   * Returns the index of the specified command in the chain.
+   * @param {occurrence} Optional param specifying which occurrence to match,
+   * with 0 representing the first occurrence.
+   */
+  indexOf: function(functionOrName, occurrence) {
+    occurrence = occurrence || 0;
+    return this.commands.findIndex(func => {
+      if (typeof functionOrName === 'string') {
+        if (func.name !== functionOrName) {
+          return false;
+        }
+      } else if (func !== functionOrName) {
+        return false;
+      }
+      if (occurrence) {
+        --occurrence;
+        return false;
+      }
+      return true;
+    });
+  },
+
+  mustHaveIndexOf: function(functionOrName, occurrence) {
+    var index = this.indexOf(functionOrName, occurrence);
+    if (index == -1) {
+      throw new Error("Unknown test: " + functionOrName);
+    }
+    return index;
+  },
+
+  /**
+   * Inserts the new commands after the specified command.
+   */
+  insertAfter: function(functionOrName, commands, all, occurrence) {
+    this._insertHelper(functionOrName, commands, 1, all, occurrence);
+  },
+
+  /**
+   * Inserts the new commands after every occurrence of the specified command
+   */
+  insertAfterEach: function(functionOrName, commands) {
+    this._insertHelper(functionOrName, commands, 1, true);
+  },
+
+  /**
+   * Inserts the new commands before the specified command.
+   */
+  insertBefore: function(functionOrName, commands, all, occurrence) {
+    this._insertHelper(functionOrName, commands, 0, all, occurrence);
+  },
+
+  _insertHelper: function(functionOrName, commands, delta, all, occurrence) {
+    occurrence = occurrence || 0;
+    for (var index = this.mustHaveIndexOf(functionOrName, occurrence);
+         index !== -1;
+         index = this.indexOf(functionOrName, ++occurrence)) {
+      this.commands = [].concat(
+        this.commands.slice(0, index + delta),
+        commands,
+        this.commands.slice(index + delta));
+      if (!all) {
+        break;
+      }
+    }
+  },
+
+  /**
+   * Removes the specified command, returns what was removed.
+   */
+  remove: function(functionOrName, occurrence) {
+    return this.commands.splice(this.mustHaveIndexOf(functionOrName, occurrence), 1);
+  },
+
+  /**
+   * Removes all commands after the specified one, returns what was removed.
+   */
+  removeAfter: function(functionOrName, occurrence) {
+    return this.commands.splice(this.mustHaveIndexOf(functionOrName, occurrence) + 1);
+  },
+
+  /**
+   * Removes all commands before the specified one, returns what was removed.
+   */
+  removeBefore: function(functionOrName, occurrence) {
+    return this.commands.splice(0, this.mustHaveIndexOf(functionOrName, occurrence));
+  },
+
+  /**
+   * Replaces a single command, returns what was removed.
+   */
+  replace: function(functionOrName, commands) {
+    this.insertBefore(functionOrName, commands);
+    return this.remove(functionOrName);
+  },
+
+  /**
+   * Replaces all commands after the specified one, returns what was removed.
+   */
+  replaceAfter: function(functionOrName, commands, occurrence) {
+    var oldCommands = this.removeAfter(functionOrName, occurrence);
+    this.append(commands);
+    return oldCommands;
+  },
+
+  /**
+   * Replaces all commands before the specified one, returns what was removed.
+   */
+  replaceBefore: function(functionOrName, commands) {
+    var oldCommands = this.removeBefore(functionOrName);
+    this.insertBefore(functionOrName, commands);
+    return oldCommands;
+  },
+
+  /**
+   * Remove all commands whose name match the specified regex.
+   */
+  filterOut: function (id_match) {
+    this.commands = this.commands.filter(c => !id_match.test(c.name));
+  },
+};
+
+function AudioStreamHelper() {
+  this._context = new AudioContext();
+}
+
+AudioStreamHelper.prototype = {
+  checkAudio: function(stream, analyser, fun) {
+    /*
+    analyser.enableDebugCanvas();
+    return analyser.waitForAnalysisSuccess(fun)
+      .then(() => analyser.disableDebugCanvas());
+    */
+    return analyser.waitForAnalysisSuccess(fun);
+  },
+
+  checkAudioFlowing: function(stream) {
+    var analyser = new AudioStreamAnalyser(this._context, stream);
+    var freq = analyser.binIndexForFrequency(TEST_AUDIO_FREQ);
+    return this.checkAudio(stream, analyser, array => array[freq] > 200);
+  },
+
+  checkAudioNotFlowing: function(stream) {
+    var analyser = new AudioStreamAnalyser(this._context, stream);
+    var freq = analyser.binIndexForFrequency(TEST_AUDIO_FREQ);
+    return this.checkAudio(stream, analyser, array => array[freq] < 50);
+  }
+}
+
+function VideoStreamHelper() {
+  this._helper = new CaptureStreamTestHelper2D(50,50);
+  this._canvas = this._helper.createAndAppendElement('canvas', 'source_canvas');
+  // Make sure this is initted
+  this._helper.drawColor(this._canvas, this._helper.green);
+  this._stream = this._canvas.captureStream(10);
+}
+
+VideoStreamHelper.prototype = {
+  stream: function() {
+    return this._stream;
+  },
+
+  startCapturingFrames: function() {
+    var i = 0;
+    var helper = this;
+    return setInterval(function() {
+      try {
+        helper._helper.drawColor(helper._canvas,
+                                 i ? helper._helper.green : helper._helper.red);
+        i = 1 - i;
+        helper._stream.requestFrame();
+      } catch (e) {
+        // ignore; stream might have shut down, and we don't bother clearing
+        // the setInterval.
+      }
+    }, 500);
+  },
+
+  waitForFrames: function(canvas, timeout_value) {
+    var intervalId = this.startCapturingFrames();
+    timeout_value = timeout_value || 8000;
+
+    return addFinallyToPromise(timeout(
+      Promise.all([
+        this._helper.waitForPixelColor(canvas, this._helper.green, 128,
+                                       canvas.id + " should become green"),
+        this._helper.waitForPixelColor(canvas, this._helper.red, 128,
+                                       canvas.id + " should become red")
+      ]),
+      timeout_value,
+      "Timed out waiting for frames")).finally(() => clearInterval(intervalId));
+  },
+
+  verifyNoFrames: function(canvas) {
+    return this.waitForFrames(canvas).then(
+      () => ok(false, "Color should not change"),
+      () => ok(true, "Color should not change")
+    );
+  }
+}
+
+
+function IsMacOSX10_6orOlder() {
+  if (navigator.platform.indexOf("Mac") !== 0) {
+    return false;
+  }
+
+  var version = Cc["@mozilla.org/system-info;1"]
+      .getService(Ci.nsIPropertyBag2)
+      .getProperty("version");
+  // the next line is correct: Mac OS 10.6 corresponds to Darwin version 10.x !
+  // Mac OS 10.7 is Darwin version 11.x. the |version| string we've got here
+  // is the Darwin version.
+  return (parseFloat(version) < 11.0);
+}
+
+(function(){
+  var el = document.createElement("link");
+  el.rel = "stylesheet";
+  el.type = "text/css";
+  el.href= "/tests/SimpleTest/test.css";
+  document.head.appendChild(el);
+}());