Combining all javascript files to one for the manual test page.

chrome/test/data/webrtc/manual/peerconnection.js

 /**
  * 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.
  */
 
+ /**
+ * See http://dev.w3.org/2011/webrtc/editor/getusermedia.html for more
+ * information on getUserMedia. See
+ * http://dev.w3.org/2011/webrtc/editor/webrtc.html for more information on
+ * peerconnection and webrtc in general.
+ */
+
+/** TODO give it a better name
+ * Global namespace object.
+ */
+var global = {};
+
 /**
- * Used as a shortcut. Moved to the top of the page due to race conditions.
+ * We need a STUN server for some API calls.
+ * @private
+ */
+var STUN_SERVER = 'stun.l.google.com:19302';
+
+/** @private */
+global.transformOutgoingSdp = function(sdp) { return sdp; };
+
+/** @private */
+global.dataStatusCallback = function(status) {};
+
+/** @private */
+global.dataCallback = function(data) {};
+
+/** @private */
+global.dtmfOnToneChange = function(tone) {};
+
+/**
+ * Used as a shortcut for finding DOM elements by ID.
  * @param {string} id is a case-sensitive string representing the unique ID of
  *     the element being sought.
  * @return {object} id returns the element object specified as a parameter
  */
 $ = function(id) {
   return document.getElementById(id);
 };
 
 /**
- * Sets the global variable gUseRtpDataChannel in message_handling.js
- * based on the check box element 'data-channel-type-rtp' checked status on
- * peerconnection.html. Also prints a help text to inform the user.
+ * Prepopulate constraints from JS to the UI. Enumerate devices available
+ * via getUserMedia, register elements to be used for local storage.
  */
-function setPcDataChannelType() {
-  var useRtpDataChannels = $('data-channel-type-rtp').checked;
-  useRtpDataChannelsForNewPeerConnections(useRtpDataChannels);
-  if (useRtpDataChannels) {
-    debug('Make sure to tick the RTP check box on both the calling and ' +
-          'answering side to ensure a data channel can be setup properly as ' +
-          'it has to use the same transport protocol (RTP to RTP and SCTP to ' +
-          'SCTP).');
+window.onload = function() {
+  hookupDataChannelCallbacks_();
+  hookupDtmfSenderCallback_();
+  updateGetUserMediaConstraints();
+  setupLocalStorageFieldValues();
+  acceptIncomingCalls();
+  if ($('get-devices-onload').checked == true) {
+    getDevices();
   }
+};
+
+/**
+ * Disconnect before the tab is closed.
+ */
+window.onbeforeunload = function() {
+  disconnect_();
+};
+
+/** TODO Add element.id as a parameter and call this function instead?
+ *  A list of element id's to be registered for local storage.
+ */
+function setupLocalStorageFieldValues() {
+  registerLocalStorage_('pc-server');
+  registerLocalStorage_('pc-createanswer-constraints');
+  registerLocalStorage_('pc-createoffer-constraints');
+  registerLocalStorage_('get-devices-onload');
 }
 
+// Public HTML functions
+
 // The *Here functions are called from peerconnection.html and will make calls
 // into our underlying JavaScript library with the values from the page
 // (have to be named differently to avoid name clashes with existing functions).
 
 function getUserMediaFromHere() {
   var constraints = $('getusermedia-constraints').value;
   try {
-    doGetUserMedia(constraints);
+    doGetUserMedia_(constraints);
   } catch (exception) {
     print_('getUserMedia says: ' + exception);
   }
 }
 
 function connectFromHere() {
   var server = $('pc-server').value;
   if ($('peer-id').value == '') {
     // Generate a random name to distinguish us from other tabs:
     $('peer-id').value = 'peer_' + Math.floor(Math.random() * 10000);
-    debug('Our name from now on will be ' + $('peer-id').value);
+    print_('Our name from now on will be ' + $('peer-id').value);
   }
   connect(server, $('peer-id').value);
 }
 
 function negotiateCallFromHere() {
-  // Set the global variables used in jsep01_call.js with values from our UI.
+  // Set the global variables with values from our UI.
   setCreateOfferConstraints(getEvaluatedJavaScript_(
       $('pc-createoffer-constraints').value));
   setCreateAnswerConstraints(getEvaluatedJavaScript_(
       $('pc-createanswer-constraints').value));
 
   ensureHasPeerConnection_();
-  try {
-    negotiateCall();
-  } catch (exception) {
-    error(exception);
-  }
+  negotiateCall_();
 }
 
 function addLocalStreamFromHere() {
   ensureHasPeerConnection_();
   addLocalStream();
 }
 
 function removeLocalStreamFromHere() {
   removeLocalStream();
 }
 
 function hangUpFromHere() {
   hangUp();
-  acceptIncomingCallsAgain();
+  acceptIncomingCalls();
 }
 
 function toggleRemoteVideoFromHere() {
   toggleRemoteStream(function(remoteStream) {
     return remoteStream.getVideoTracks()[0];
   }, 'video');
 }
 
 function toggleRemoteAudioFromHere() {
   toggleRemoteStream(function(remoteStream) {
@@ skipping 62 matching lines @@
  * resolution else it defaults to 640x480 in the constraints for screen
  * capturing.
  */
 function updateGetUserMediaConstraints() {
   var audio_selected = $('audiosrc');
   var video_selected = $('videosrc');
   var constraints = {
     audio: $('audio').checked,
     video: $('video').checked
   };
+
   if (audio_selected.disabled == false && video_selected.disabled == false) {
-    var devices = getSourcesFromField(audio_selected, video_selected);
+    var devices = getSourcesFromField_(audio_selected, video_selected);
     if ($('audio').checked == true) {
       if (devices.audio_id != null) {
         constraints.audio = {optional: [{sourceId: devices.audio_id}]};
-      }
-      else {
+      } else {
         constraints.audio = true;
       }
     }
     if ($('video').checked == true) {
       // Default optional constraints placed here.
       constraints.video = {optional: [{minWidth: $('video-width').value},
                                       {minHeight: $('video-height').value},
                                       {googCpuOveruseDetection: true},
                                       {googLeakyBucket: true}]
       };
       if (devices.video_id != null) {
         constraints.video.optional.push({sourceId: devices.video_id});
       }
     }
   }
+
   if ($('screencapture').checked) {
     var constraints = {
       audio: $('audio').checked,
       video: {mandatory: {chromeMediaSource: 'screen',
                           maxWidth: screen.width,
                           maxHeight: screen.height}}
     };
     if ($('audio').checked == true)
-      debug('Audio for screencapture is not implemented yet, please ' +
+      print_('Audio for screencapture is not implemented yet, please ' +
             'try to set audio = false prior requesting screencapture');
   }
-  $('getusermedia-constraints').value =
-      JSON.stringify(constraints, null, ' ');
+  $('getusermedia-constraints').value = JSON.stringify(constraints, null, ' ');
 }
 
 function showServerHelp() {
   alert('You need to build and run a peerconnection_server on some ' +
         'suitable machine. To build it in chrome, just run make/ninja ' +
         'peerconnection_server. Otherwise, read in https://code.google' +
         '.com/searchframe#xSWYf0NTG_Q/trunk/peerconnection/README&q=REA' +
         'DME%20package:webrtc%5C.googlecode%5C.com.');
 }
 
-function toggleHelp() {
-  var help = $('help');
-  if (help.style.display == 'none')
-    help.style.display = 'inline';
-  else
-    help.style.display = 'none';
-}
-
 function clearLog() {
   $('messages').innerHTML = '';
   $('debug').innerHTML = '';
 }
 
 /**
- * Prepopulate constraints from JS to the UI and setup callbacks in the scripts
- * shared with browser tests or automated tests. Enumerates devices available
- * via getUserMedia.
- */
-window.onload = function() {
-  $('pc-createoffer-constraints').value = JSON.stringify(
-      gCreateOfferConstraints, null, ' ');
-  $('pc-createanswer-constraints').value = JSON.stringify(
-    gCreateAnswerConstraints, null, ' ');
-  replaceReturnCallback(print_);
-  replaceDebugCallback(debug_);
-  doNotAutoAddLocalStreamWhenCalled();
-  hookupDataChannelCallbacks_();
-  hookupDtmfSenderCallback_();
-  displayVideoSize_($('local-view'));
-  displayVideoSize_($('remote-view'));
-  updateGetUserMediaConstraints();
-  setPcDataChannelType();
-  setupLocalStorageFieldValues();
-  if ($('get-devices-onload').checked == true) {
-    getDevices();
-  }
-};
+ * Stops the local stream.
+ */
+function stopLocalStream() {
+  if (global.localStream == null)
+    error_('Tried to stop local stream, ' +
+           'but media access is not granted.');
+
+  global.localStream.stop();
+}
+
+/**
+ * Adds the current local media stream to a peer connection.
+ * @param {RTCPeerConnection} peerConnection
+ */
+function addLocalStreamToPeerConnection(peerConnection) {
+  if (global.localStream == null)
+    error_('Tried to add local stream to peer connection, but there is no ' +
+           'stream yet.');
+  try {
+    peerConnection.addStream(global.localStream, global.addStreamConstraints);
+  } catch (exception) {
+    error_('Failed to add stream with constraints ' +
+           global.addStreamConstraints + ': ' + exception);
+  }
+  print_('Added local stream.');
+}
+
+/**
+ * Removes the local stream from the peer connection.
+ * @param {rtcpeerconnection} peerConnection
+ */
+function removeLocalStreamFromPeerConnection(peerConnection) {
+  if (global.localStream == null)
+    error_('Tried to remove local stream from peer connection, but there is ' +
+           'no stream yet.');
+  try {
+    peerConnection.removeStream(global.localStream);
+  } catch (exception) {
+    error_('Could not remove stream: ' + exception);
+  }
+  print_('Removed local stream.');
+}
+
+/**
+ * Enumerates the audio and video devices available in Chrome and adds the
+ * devices to the HTML elements with Id 'audiosrc' and 'videosrc'.
+ * Checks if device enumeration is supported and if the 'audiosrc' + 'videosrc'
+ * elements exists, if not a debug printout will be displayed.
+ * If the device label is empty, audio/video + sequence number will be used to
+ * populate the name. Also makes sure the children has been loaded in order
+ * to update the constraints.
+ */
+function getDevices() {
+  var audio_select = $('audiosrc');
+  var video_select = $('videosrc');
+  var get_devices = $('get-devices');
+  audio_select.innerHTML = '';
+  video_select.innerHTML = '';
+  try {
+    eval(MediaStreamTrack.getSources(function() {}));
+  } catch (exception) {
+    audio_select.disabled = true;
+    video_select.disabled = true;
+    refresh_devices.disabled = true;
+    updateGetUserMediaConstraints();
+    error_('Device enumeration not supported. ' + exception);
+  }
+  MediaStreamTrack.getSources(function(devices) {
+    for (var i = 0; i < devices.length; i++) {
+      var option = document.createElement('option');
+      option.value = devices[i].id;
+      option.text = devices[i].label;
+      if (devices[i].kind == 'audio') {
+        if (option.text == '') {
+          option.text = devices[i].id;
+        }
+        audio_select.appendChild(option);
+      } else if (devices[i].kind == 'video') {
+        if (option.text == '') {
+          option.text = devices[i].id;
+        }
+        video_select.appendChild(option);
+      } else {
+        error_('Device type ' + devices[i].kind + ' not recognized, ' +
+                'cannot enumerate device. Currently only device types' +
+                '\'audio\' and \'video\' are supported');
+        updateGetUserMediaConstraints();
+        return;
+      }
+    }
+  });
+  checkIfDeviceDropdownsArePopulated_();
+}
+
+/**
+ * Sets the transform to apply just before setting the local description and
+ * sending to the peer.
+ * @param {function} transformFunction A function which takes one SDP string as
+ *     argument and returns the modified SDP string.
+ */
+function setOutgoingSdpTransform(transformFunction) {
+  global.transformOutgoingSdp = transformFunction;
+}
+
+/**
+ * Sets the MediaConstraints to be used for PeerConnection createAnswer() calls.
+ * @param {string} mediaConstraints The constraints, as defined in the
+ *     PeerConnection JS API spec.
+ */
+function setCreateAnswerConstraints(mediaConstraints) {
+  global.createAnswerConstraints = mediaConstraints;
+}
+
+/**
+ * Sets the MediaConstraints to be used for PeerConnection createOffer() calls.
+ * @param {string} mediaConstraints The constraints, as defined in the
+ *     PeerConnection JS API spec.
+ */
+function setCreateOfferConstraints(mediaConstraints) {
+  global.createOfferConstraints = mediaConstraints;
+}
+
+/**
+ * Sets the callback functions that will receive DataChannel readyState updates
+ * and received data.
+ * @param {function} status_callback The function that will receive a string
+ * with
+ *     the current DataChannel readyState.
+ * @param {function} data_callback The function that will a string with data
+ *     received from the remote peer.
+ */
+function setDataCallbacks(status_callback, data_callback) {
+  global.dataStatusCallback = status_callback;
+  global.dataCallback = data_callback;
+}
+
+/**
+ * Sends data on an active DataChannel.
+ * @param {string} data The string that will be sent to the remote peer.
+ */
+function sendDataOnChannel(data) {
+  if (global.dataChannel == null)
+    error_('Trying to send data, but there is no DataChannel.');
+  global.dataChannel.send(data);
+}
+
+/**
+ * Sets the callback function that will receive DTMF sender ontonechange events.
+ * @param {function} ontonechange The function that will receive a string with
+ *     the tone that has just begun playout.
+ */
+function setOnToneChange(ontonechange) {
+  global.dtmfOnToneChange = ontonechange;
+}
+
+/**
+ * Inserts DTMF tones on an active DTMF sender.
+ * @param {string} tones to be sent.
+ * @param {string} duration duration of the tones to be sent.
+ * @param {string} interToneGap gap between the tones to be sent.
+ */
+function insertDtmf(tones, duration, interToneGap) {
+  if (global.dtmfSender == null)
+    error_('Trying to send DTMF, but there is no DTMF sender.');
+  global.dtmfSender.insertDTMF(tones, duration, interToneGap);
+}
+
+function handleMessage(peerConnection, message) {
+  var parsed_msg = JSON.parse(message);
+  if (parsed_msg.type) {
+    var session_description = new RTCSessionDescription(parsed_msg);
+    peerConnection.setRemoteDescription(
+        session_description,
+        function() { success_('setRemoteDescription'); },
+        function() { failure_('setRemoteDescription'); });
+    if (session_description.type == 'offer') {
+      print_('createAnswer with constraints: ' +
+            JSON.stringify(global.createAnswerConstraints, null, ' '));
+      peerConnection.createAnswer(
+        setLocalAndSendMessage_,
+        function() { failure_('createAnswer'); },
+        global.createAnswerConstraints);
+    }
+    return;
+  } else if (parsed_msg.candidate) {
+    var candidate = new RTCIceCandidate(parsed_msg);
+    peerConnection.addIceCandidate(candidate);
+    return;
+  }
+  error_('unknown message received');
+}
+
+function createPeerConnection(stun_server, useRtpDataChannels) {
+  servers = {iceServers: [{url: 'stun:' + stun_server}]};
+  try {
+    var constraints = { optional: [{ RtpDataChannels: useRtpDataChannels }]};
+    peerConnection = new webkitRTCPeerConnection(servers, constraints);
+  } catch (exception) {
+    error_('Failed to create peer connection: ' + exception);
+  }
+  peerConnection.onaddstream = addStreamCallback_;
+  peerConnection.onremovestream = removeStreamCallback_;
+  peerConnection.onicecandidate = iceCallback_;
+  peerConnection.ondatachannel = onCreateDataChannelCallback_;
+  return peerConnection;
+}
+
+function setupCall(peerConnection) {
+  print_('createOffer with constraints: ' +
+        JSON.stringify(global.createOfferConstraints, null, ' '));
+  peerConnection.createOffer(
+      setLocalAndSendMessage_,
+      function() { failure_('createOffer'); },
+      global.createOfferConstraints);
+}
+
+function answerCall(peerConnection, message) {
+  handleMessage(peerConnection, message);
+}
+
+function createDataChannel(peerConnection, label) {
+  if (global.dataChannel != null && global.dataChannel.readyState != 'closed')
+    error_('Creating DataChannel, but we already have one.');
+
+  global.dataChannel = peerConnection.createDataChannel(label,
+                                                        { reliable: false });
+  print_('DataChannel with label ' + global.dataChannel.label + ' initiated ' +
+         'locally.');
+  hookupDataChannelEvents();
+}
+
+function closeDataChannel(peerConnection) {
+  if (global.dataChannel == null)
+    error_('Closing DataChannel, but none exists.');
+  print_('DataChannel with label ' + global.dataChannel.label +
+         ' is beeing closed.');
+  global.dataChannel.close();
+}
+
+function createDtmfSender(peerConnection) {
+  if (global.dtmfSender != null)
+    error_('Creating DTMF sender, but we already have one.');
+
+  var localStream = global.localStream();
+  if (localStream == null)
+    error_('Creating DTMF sender but local stream is null.');
+  local_audio_track = localStream.getAudioTracks()[0];
+  global.dtmfSender = peerConnection.createDTMFSender(local_audio_track);
+  global.dtmfSender.ontonechange = global.dtmfOnToneChange;
+}
+
+/**
+ * Connects to the provided peerconnection_server.
+ *
+ * @param {string} serverUrl The server URL in string form without an ending
+ *     slash, something like http://localhost:8888.
+ * @param {string} clientName The name to use when connecting to the server.
+ */
+function connect(serverUrl, clientName) {
+  if (global.ourPeerId != null)
+    error_('connecting, but is already connected.');
+
+  print_('Connecting to ' + serverUrl + ' as ' + clientName);
+  global.serverUrl = serverUrl;
+  global.ourClientName = clientName;
+
+  request = new XMLHttpRequest();
+  request.open('GET', serverUrl + '/sign_in?' + clientName, true);
+  print_(serverUrl + '/sign_in?' + clientName);
+  request.onreadystatechange = function() {
+    connectCallback_(request);
+  };
+  request.send();
+}
+
+/**
+ * Checks if the remote peer has connected. Returns peer-connected if that is
+ * the case, otherwise no-peer-connected.
+ */
+function remotePeerIsConnected() {
+  if (global.remotePeerId == null)
+    print_('no-peer-connected');
+  else
+    print_('peer-connected');
+}
+
+/**
+ * Creates a peer connection. Must be called before most other public functions
+ * in this file.
+ */
+function preparePeerConnection() {
+  if (global.peerConnection != null)
+    error_('creating peer connection, but we already have one.');
+
+  global.useRtpDataChannels = $('data-channel-type-rtp').checked;
+  global.peerConnection = createPeerConnection(STUN_SERVER,
+                                               global.useRtpDataChannels);
+  print_('ok-peerconnection-created');
+}
+
+/**
+ * Adds the local stream to the peer connection. You will have to re-negotiate
+ * the call for this to take effect in the call.
+ */
+function addLocalStream() {
+  if (global.peerConnection == null)
+    error_('adding local stream, but we have no peer connection.');
+
+  addLocalStreamToPeerConnection(global.peerConnection);
+  print_('ok-added');
+}
+
+/**
+ * Removes the local stream from the peer connection. You will have to
+ * re-negotiate the call for this to take effect in the call.
+ */
+function removeLocalStream() {
+  if (global.peerConnection == null)
+    error_('attempting to remove local stream, but no call is up');
+
+  removeLocalStreamFromPeerConnection(global.peerConnection);
+  print_('ok-local-stream-removed');
+}
+
+/**
+ * (see getReadyState_)
+ */
+function getPeerConnectionReadyState() {
+  print_(getReadyState_());
+}
+
+/**
+ * Toggles the remote audio stream's enabled state on the peer connection, given
+ * that a call is active. Returns ok-[typeToToggle]-toggled-to-[true/false]
+ * on success.
+ *
+ * @param {function} selectAudioOrVideoTrack A function that takes a remote
+ *     stream as argument and returns a track (e.g. either the video or audio
+ *     track).
+ * @param {function} typeToToggle Either "audio" or "video" depending on what
+ *     the selector function selects.
+ */
+function toggleRemoteStream(selectAudioOrVideoTrack, typeToToggle) {
+  if (global.peerConnection == null)
+    error_('Tried to toggle remote stream, but have no peer connection.');
+  if (global.peerConnection.getRemoteStreams().length == 0)
+    error_('Tried to toggle remote stream, but not receiving any stream.');
+
+  var track = selectAudioOrVideoTrack(
+      global.peerConnection.getRemoteStreams()[0]);
+  toggle_(track, 'remote', typeToToggle);
+}
+
+/**
+ * See documentation on toggleRemoteStream (this function is the same except
+ * we are looking at local streams).
+ */
+function toggleLocalStream(selectAudioOrVideoTrack, typeToToggle) {
+  if (global.peerConnection == null)
+    error_('Tried to toggle local stream, but have no peer connection.');
+  if (global.peerConnection.getLocalStreams().length == 0)
+    error_('Tried to toggle local stream, but there is no local stream in ' +
+           'the call.');
+
+  var track = selectAudioOrVideoTrack(
+      global.peerConnection.getLocalStreams()[0]);
+  toggle_(track, 'local', typeToToggle);
+}
+
+/**
+ * Hangs up a started call. Returns ok-call-hung-up on success. This tab will
+ * not accept any incoming calls after this call.
+ */
+function hangUp() {
+  if (global.peerConnection == null)
+    error_('hanging up, but has no peer connection');
+  if (getReadyState_() != 'active')
+    error_('hanging up, but ready state is not active (no call up).');
+  sendToPeer(global.remotePeerId, 'BYE');
+  closeCall_();
+  global.acceptsIncomingCalls = false;
+  print_('ok-call-hung-up');
+}
+
+/**
+ * Start accepting incoming calls.
+ */
+function acceptIncomingCalls() {
+  global.acceptsIncomingCalls = true;
+}
+
+/**
+ * Creates a DataChannel on the current PeerConnection. Only one DataChannel can
+ * be created on each PeerConnection.
+ * Returns ok-datachannel-created on success.
+ */
+function createDataChannelOnPeerConnection() {
+  if (global.peerConnection == null)
+    error_('Tried to create data channel, but have no peer connection.');
+
+  createDataChannel(global.peerConnection, global.ourClientName);
+  print_('ok-datachannel-created');
+}
+
+/**
+ * Close the DataChannel on the current PeerConnection.
+ * Returns ok-datachannel-close on success.
+ */
+function closeDataChannelOnPeerConnection() {
+  if (global.peerConnection == null)
+    error_('Tried to close data channel, but have no peer connection.');
+
+  closeDataChannel(global.peerConnection);
+  print_('ok-datachannel-close');
+}
+
+/**
+ * Creates a DTMF sender on the current PeerConnection.
+ * Returns ok-dtmfsender-created on success.
+ */
+function createDtmfSenderOnPeerConnection() {
+  if (global.peerConnection == null)
+    error_('Tried to create DTMF sender, but have no peer connection.');
+
+  createDtmfSender(global.peerConnection);
+  print_('ok-dtmfsender-created');
+}
+
+/**
+ * Send DTMF tones on the global.dtmfSender.
+ * Returns ok-dtmf-sent on success.
+ */
+function insertDtmfOnSender(tones, duration, interToneGap) {
+  if (global.dtmfSender == null)
+    error_('Tried to insert DTMF tones, but have no DTMF sender.');
+
+  insertDtmf(tones, duration, interToneGap);
+  print_('ok-dtmf-sent');
+}
+
+/**
+ * Sends a message to a peer through the peerconnection_server.
+ */
+function sendToPeer(peer, message) {
+  var messageToLog = message.sdp ? message.sdp : message;
+  print_('Sending message ' + messageToLog + ' to peer ' + peer + '.');
+
+  var request = new XMLHttpRequest();
+  var url = global.serverUrl + '/message?peer_id=' + global.ourPeerId + '&to=' +
+      peer;
+  request.open('POST', url, false);
+  request.setRequestHeader('Content-Type', 'text/plain');
+  request.send(message);
+}
+
+/**
+ * @param {!string} videoTagId The ID of the video tag to update.
+ * @param {!string} width The width of the video to update the video tag, if
+ *     width or height is 0, size will be taken from videoTag.videoWidth.
+ * @param {!string} height The height of the video to update the video tag, if
+ *     width or height is 0 size will be taken from the videoTag.videoHeight.
+ */
+function updateVideoTagSize(videoTagId, width, height) {
+  var videoTag = $(videoTagId);
+  if (width > 0 || height > 0) {
+    videoTag.width = width;
+    videoTag.height = height;
+  }
+  else {
+    if (videoTag.videoWidth > 0 || videoTag.videoHeight > 0) {
+      videoTag.width = videoTag.videoWidth;
+      videoTag.height = videoTag.videoHeight;
+    }
+    else {
+      print_('"' + videoTagId + '" video stream size is 0, skipping resize');
+    }
+  }
+  print_('Set video tag "' + videoTagId + '" size to ' + videoTag.width + 'x' +
+         videoTag.height);
+  displayVideoSize_(videoTag);
+}
+
+// Internals.
+
+/**
+ * Disconnects from the peerconnection server. Returns ok-disconnected on
+ * success.
+ */
+function disconnect_() {
+  if (global.ourPeerId == null)
+    return;
+
+  request = new XMLHttpRequest();
+  request.open('GET', global.serverUrl + '/sign_out?peer_id=' +
+               global.ourPeerId, false);
+  request.send();
+  global.ourPeerId = null;
+  print_('ok-disconnected');
+}
+
+/**
+* Returns true if we are disconnected from peerconnection_server.
+*/
+function isDisconnected_() {
+  return global.ourPeerId == null;
+}
+
+/**
+ * @private
+ * @return {!string} The current peer connection's ready state, or
+ *     'no-peer-connection' if there is no peer connection up.
+ *
+ * NOTE: The PeerConnection states are changing and until chromium has
+ *       implemented the new states we have to use this interim solution of
+ *       always assuming that the PeerConnection is 'active'.
+ */
+function getReadyState_() {
+  if (global.peerConnection == null)
+    return 'no-peer-connection';
+
+  return 'active';
+}
+
+/**
+ * This function asks permission to use the webcam and mic from the browser. It
+ * will return ok-requested to the test. This does not mean the request was
+ * approved though. The test will then have to click past the dialog that
+ * appears in Chrome, which will run either the OK or failed callback as a
+ * a result. To see which callback was called, use obtainGetUserMediaResult_().
+ * @private
+ * @param {string} constraints Defines what to be requested, with mandatory
+ *     and optional constraints defined. The contents of this parameter depends
+ *     on the WebRTC version. This should be JavaScript code that we eval().
+ */
+function doGetUserMedia_(constraints) {
+  if (!getUserMedia) {
+    print_('Browser does not support WebRTC.');
+    return;
+  }
+  try {
+    var evaluatedConstraints;
+    eval('evaluatedConstraints = ' + constraints);
+  } catch (exception) {
+    error_('Not valid JavaScript expression: ' + constraints);
+  }
+  print_('Requesting doGetUserMedia: constraints: ' + constraints);
+  getUserMedia(evaluatedConstraints, getUserMediaOkCallback_,
+               getUserMediaFailedCallback_);
+}
+
+/**
+ * Must be called after calling doGetUserMedia.
+ * @private
+ * @return {string} Returns not-called-yet if we have not yet been called back
+ *     by WebRTC. Otherwise it returns either ok-got-stream or
+ *     failed-with-error-x (where x is the error code from the error
+ *     callback) depending on which callback got called by WebRTC.
+ */
+function obtainGetUserMediaResult_() {
+  if (global.requestWebcamAndMicrophoneResult == null)
+    global.requestWebcamAndMicrophoneResult = ' not called yet';
+
+  return global.requestWebcamAndMicrophoneResult;
+
+}
+
+/**
+ * Negotiates a call with the other side. This will create a peer connection on
+ * the other side if there isn't one.
+ *
+ * To call this method we need to be aware of the other side, e.g. we must be
+ * connected to peerconnection_server and we must have exactly one peer on that
+ * server.
+ *
+ * This method may be called any number of times. If you haven't added any
+ * streams to the call, an "empty" call will result. The method will return
+ * ok-negotiating immediately to the test if the negotiation was successfully
+ * sent.
+ * @private
+ */
+function negotiateCall_() {
+  if (global.peerConnection == null)
+    error_('Negotiating call, but we have no peer connection.');
+  if (global.ourPeerId == null)
+    error_('Negotiating call, but not connected.');
+  if (global.remotePeerId == null)
+    error_('Negotiating call, but missing remote peer.');
+
+  setupCall(global.peerConnection);
+  print_('ok-negotiating');
+}
+
+/**
+ * This provides the selected source id from the objects in the parameters
+ * provided to this function. If the audio_select or video_select objects does
+ * not have any HTMLOptions children it will return null in the source object.
+ * @param {object} audio_select HTML drop down element with audio devices added
+ *     as HTMLOptionsCollection children.
+ * @param {object} video_select HTML drop down element with audio devices added
+ *     as HTMLPptionsCollection children.
+ * @return {object} audio_id video_id Containing audio and video source ID from
+ *     the selected devices in the drop down menus provided as parameters to
+ *     this function.
+ * @private
+ */
+function getSourcesFromField_(audio_select, video_select) {

[kjellander_chromium, 2014/01/07 10:34:17]

Please correct the function parameter variable names that have underscores to
follow the convention: variableNamesLikeThis 
Or to that in a separate CL: your choice.

http://google-styleguide.googlecode.com/svn/trunk/javascriptguide.xml?showone...

+  var source = {
+    audio_id: null,
+    video_id: null
+  };
+  if (audio_select.options.length > 0) {
+    source.audio_id = audio_select.options[audio_select.selectedIndex].value;
+  }
+  if (video_select.options.length > 0) {
+    source.video_id = video_select.options[video_select.selectedIndex].value;
+  }
+  return source;
+}
+
+/**
+ * @private
+ * @param {NavigatorUserMediaError} error Error containing details.
+ */
+function getUserMediaFailedCallback_(error) {
+  print_('GetUserMedia FAILED: Maybe the camera is in use by another process?');
+  gRequestWebcamAndMicrophoneResult = 'failed-with-error-' + error.name;
+  print_(gRequestWebcamAndMicrophoneResult);
+}
+
+/** @private */
+function success_(method) {
+  print_(method + '(): success.');
+}
+
+/** @private */
+function failure_(method, error) {
+  error_(method + '() failed: ' + error);
+}
+
+/** @private */
+function iceCallback_(event) {
+  if (event.candidate)
+    sendToPeer(global.remotePeerId, JSON.stringify(event.candidate));
+}
+
+/** @private */
+function setLocalAndSendMessage_(session_description) {
+  session_description.sdp =
+    global.transformOutgoingSdp(session_description.sdp);
+  global.peerConnection.setLocalDescription(
+    session_description,
+    function() { success_('setLocalDescription'); },
+    function() { failure_('setLocalDescription'); });
+  print_('Sending SDP message:\n' + session_description.sdp);
+  sendToPeer(global.remotePeerId, JSON.stringify(session_description));
+}
+
+/** @private */
+function addStreamCallback_(event) {
+  print_('Receiving remote stream...');
+  var videoTag = document.getElementById('remote-view');
+  attachMediaStream(videoTag, event.stream);
+
+  window.addEventListener('loadedmetadata', function() {
+     displayVideoSize_(videoTag);}, true);
+}
+
+/** @private */
+function removeStreamCallback_(event) {
+  print_('Call ended.');
+  document.getElementById('remote-view').src = '';
+}
+
+/** @private */
+function onCreateDataChannelCallback_(event) {
+  if (global.dataChannel != null && global.dataChannel.readyState != 'closed') {
+    error_('Received DataChannel, but we already have one.');
+  }
+
+  global.dataChannel = event.channel;
+  print_('DataChannel with label ' + global.dataChannel.label +
+            ' initiated by remote peer.');
+  hookupDataChannelEvents();
+}
+
+/** @private */
+function hookupDataChannelEvents() {
+  global.dataChannel.onmessage = global.dataCallback;
+  global.dataChannel.onopen = onDataChannelReadyStateChange_;
+  global.dataChannel.onclose = onDataChannelReadyStateChange_;
+  // Trigger global.dataStatusCallback so an application is notified
+  // about the created data channel.
+  onDataChannelReadyStateChange_();
+}
+
+/** @private */
+function onDataChannelReadyStateChange_() {
+  var readyState = global.dataChannel.readyState;
+  print_('DataChannel state:' + readyState);
+  global.dataStatusCallback(readyState);
+}
+
+/**
+ * @private
+ * @param {MediaStream} stream Media stream.
+ */
+function getUserMediaOkCallback_(stream) {
+  global.localStream = stream;
+  global.requestWebcamAndMicrophoneResult = 'ok-got-stream';
+
+  if (stream.getVideoTracks().length > 0) {
+    // Show the video tag if we did request video in the getUserMedia call.
+    var videoTag = $('local-view');
+    attachMediaStream(videoTag, stream);
+
+   window.addEventListener('loadedmetadata', function() {
+       displayVideoSize_(videoTag);}, true);
+  }
+}
+
+/**
+ * @private
+ * @param {string} videoTag The ID of the video tag + stream used to
+ *     write the size to a HTML tag based on id if the div's exists.
+ */
+function displayVideoSize_(videoTag) {
+  if ($(videoTag.id + '-stream-size') && $(videoTag.id + '-size')) {
+    if (videoTag.videoWidth > 0 || videoTag.videoHeight > 0) {
+      $(videoTag.id + '-stream-size').innerHTML = '(stream size: ' +
+                                                  videoTag.videoWidth + 'x' +
+                                                  videoTag.videoHeight + ')';
+      $(videoTag.id + '-size').innerHTML = videoTag.width + 'x' +
+                                           videoTag.height;
+    }
+  } else {
+    print_('Skipping updating -stream-size and -size tags due to div\'s ' +
+           'are missing');
+  }
+}
 
 /**
  * Checks if the 'audiosrc' and 'videosrc' drop down menu elements has had all
  * of its children appended in order to provide device ID's to the function
  * 'updateGetUserMediaConstraints()', used in turn to populate the getUserMedia
- * constraints text box when the page has loaded. If not the user is informed
- * and instructions on how to populate the field is provided.
- */
-function checkIfDeviceDropdownsArePopulated() {
+ * constraints text box when the page has loaded.
+ * @private
+ */
+function checkIfDeviceDropdownsArePopulated_() {
   if (document.addEventListener) {
     $('audiosrc').addEventListener('DOMNodeInserted',
          updateGetUserMediaConstraints, false);
     $('videosrc').addEventListener('DOMNodeInserted',
          updateGetUserMediaConstraints, false);
-  }
-  else {
-    debug('addEventListener is not supported by your browser, cannot update ' +
-          'device source ID\'s automatically. Select a device from the audio ' +
-          'or video source drop down menu to update device source id\'s');
-  }
-}
-
-/**
- * Disconnect before the tab is closed.
- */
-window.onbeforeunload = function() {
-  if (!isDisconnected())
-    disconnect();
-};
-
-// Internals.
+  } else {
+    print_('addEventListener is not supported by your browser, cannot update ' +
+           'device source ID\'s automatically. Select a device from the audio' +
+           ' or video source drop down menu to update device source id\'s');
+  }
+}
+
+/**
+ * Register an input element to use local storage to remember its state between
+ * sessions (using local storage). Only input elements are supported.
+ * @private
+ * @param {!string} element_id to be used as a key for local storage and the id
+ *     of the element to store the state for.
+ */
+function registerLocalStorage_(element_id) {
+  var element = $(element_id);
+  if (element.tagName != 'INPUT') {
+    error_('You can only use registerLocalStorage_ for input elements. ' +
+          'Element \"' + element.tagName + '\" is not an input element. ');
+  }
+
+  if (localStorage.getItem(element.id) == 'undefined') {
+    storeLocalStorageField_(element);
+  } else {
+    getLocalStorageField_(element);
+  }
+  // Registers the appropriate events for input elements.
+  if (element.type == 'checkbox') {
+    element.onclick = function() { storeLocalStorageField_(this); };
+  } else if (element.type == 'text') {
+    element.onblur = function() { storeLocalStorageField_(this); };
+  } else {
+    error_('Unsupportered input type: ' + '\"' + element.type + '\"');
+  }
+}
+
+/**
+ * Fetches the stored values from local storage and updates checkbox status.
+ * @private
+ * @param {!Object} element of which id is representing the key parameter for
+ *     local storage.
+ */
+function getLocalStorageField_(element) {
+  // Makes sure the checkbox status is matching the local storage value.
+  if (element.type == 'checkbox') {
+    element.checked = (localStorage.getItem(element.id) == 'true');
+  } else if (element.type == 'text') {
+    element.value = localStorage.getItem(element.id);
+  } else {
+    error_('Unsupportered input type: ' + '\"' + element.type + '\"');
+  }
+}
+
+/**
+ * Stores the string value of the element object using local storage.
+ * @private
+ * @param {!Object} element of which id is representing the key parameter for
+ *     local storage.
+ */
+function storeLocalStorageField_(element) {
+  if (element.type == 'checkbox') {
+    localStorage.setItem(element.id, element.checked);
+  } else if (element.type == 'text') {
+    localStorage.setItem(element.id, element.value);
+  }
+}
 
 /**
  * Create the peer connection if none is up (this is just convenience to
  * avoid having a separate button for that).
  * @private
  */
 function ensureHasPeerConnection_() {
-  if (getReadyState() == 'no-peer-connection') {
+  if (getReadyState_() == 'no-peer-connection') {
     preparePeerConnection();
   }
 }
 
 /**
  * @private
  * @param {string} message Text to print.
  */
 function print_(message) {
-  // Filter out uninteresting noise.
-  if (message == 'ok-no-errors')
-    return;
-
   console.log(message);
   $('messages').innerHTML += message + '<br>';
 }
 
 /**
  * @private
  * @param {string} message Text to print.
  */
 function debug_(message) {
   console.log(message);
   $('debug').innerHTML += message + '<br>';
 }
 
 /**
  * Print error message in the debug log + JS console and throw an Error.
  * @private
  * @param {string} message Text to print.
  */
-function error(message) {
+function error_(message) {
   $('debug').innerHTML += '<span style="color:red;">' + message + '</span><br>';
   throw new Error(message);
 }
 
 /**
  * @private
  * @param {string} stringRepresentation JavaScript as a string.
  * @return {Object} The PeerConnection constraints as a JavaScript dictionary.
  */
 function getEvaluatedJavaScript_(stringRepresentation) {
   try {
     var evaluatedJavaScript;
     eval('evaluatedJavaScript = ' + stringRepresentation);
     return evaluatedJavaScript;
   } catch (exception) {
-    error('Not valid JavaScript expression: ' + stringRepresentation);
+    error_('Not valid JavaScript expression: ' + stringRepresentation);
   }
 }
 
 /**
  * Swaps lines within a SDP message.
  * @private
  * @param {string} sdp The full SDP message.
  * @param {string} line The line to swap with swapWith.
  * @param {string} swapWith The other line.
  * @return {string} The altered SDP message.
  */
 function swapSdpLines_(sdp, line, swapWith) {
   var lines = sdp.split('\r\n');
   var lineStart = lines.indexOf(line);
   var swapLineStart = lines.indexOf(swapWith);
   if (lineStart == -1 || swapLineStart == -1)
     return sdp;  // This generally happens on the first message.
 
   var tmp = lines[lineStart];
   lines[lineStart] = lines[swapLineStart];
   lines[swapLineStart] = tmp;
 
   return lines.join('\r\n');
 }
 
-// TODO(phoglund): Not currently used; delete once it clear we do not need to
-// test opus prioritization.
-/** @private */
-function preferOpus_() {
-  setOutgoingSdpTransform(function(sdp) {
-    sdp = sdp.replace('103 104 111', '111 103 104');
-
-    // TODO(phoglund): We need to swap the a= lines too. I don't think this
-    // should be needed but it apparently is right now.
-    return swapSdpLines_(sdp,
-                         'a=rtpmap:103 ISAC/16000',
-                         'a=rtpmap:111 opus/48000');
-  });
-}
-
 /** @private */
 function forceIsac_() {
   setOutgoingSdpTransform(function(sdp) {
     // Remove all other codecs (not the video codecs though).
     sdp = sdp.replace(/m=audio (\d+) RTP\/SAVPF.*\r\n/g,
                       'm=audio $1 RTP/SAVPF 104\r\n');
     sdp = sdp.replace('a=fmtp:111 minptime=10', 'a=fmtp:104 minptime=10');
     sdp = sdp.replace(/a=rtpmap:(?!104)\d{1,3} (?!VP8|red|ulpfec).*\r\n/g, '');
     return sdp;
   });
 }
 
 /** @private */
 function dontTouchSdp_() {
   setOutgoingSdpTransform(function(sdp) { return sdp; });
 }
 
 /** @private */
 function hookupDataChannelCallbacks_() {
   setDataCallbacks(function(status) {
     $('data-channel-status').value = status;
   },
   function(data_message) {
-    debug('Received ' + data_message.data);
+    print_('Received ' + data_message.data);
     $('data-channel-receive').value =
       data_message.data + '\n' + $('data-channel-receive').value;
   });
 }
 
 /** @private */
 function hookupDtmfSenderCallback_() {
   setOnToneChange(function(tone) {
-    debug('Sent DTMF tone: ' + tone.tone);
+    print_('Sent DTMF tone: ' + tone.tone);
     $('dtmf-tones-sent').value =
       tone.tone + '\n' + $('dtmf-tones-sent').value;
   });
 }
 
-/**
- * A list of element id's to be registered for local storage.
- */
-function setupLocalStorageFieldValues() {
-  registerLocalStorage_('pc-server');
-  registerLocalStorage_('pc-createanswer-constraints');
-  registerLocalStorage_('pc-createoffer-constraints');
-  registerLocalStorage_('get-devices-onload');
+/** @private */
+function toggle_(track, localOrRemote, audioOrVideo) {
+  if (!track)
+    error_('Tried to toggle ' + localOrRemote + ' ' + audioOrVideo +
+                 ' stream, but has no such stream.');
+
+  track.enabled = !track.enabled;
+  print_('ok-' + audioOrVideo + '-toggled-to-' + track.enabled);
 }
 
-/**
- * Register an input element to use local storage to remember its state between
- * sessions (using local storage). Only input elements are supported.
- * @private
- * @param {!string} element_id to be used as a key for local storage and the id
- *     of the element to store the state for.
- */
-function registerLocalStorage_(element_id) {
-  var element = $(element_id);
-  if (element.tagName != 'INPUT') {
-    error('You can only use registerLocalStorage_ for input elements. ' +
-          'Element \"' + element.tagName +'\" is not an input element. ');
+/** @private */
+function connectCallback_(request) {
+  print_('Connect callback: ' + request.status + ', ' + request.readyState);
+  if (request.status == 0) {
+    print_('peerconnection_server doesn\'t seem to be up.');
+    print_('failed-to-connect');
   }
-
-  if (localStorage.getItem(element.id) == 'undefined') {
-    storeLocalStorageField_(element);
-  } else {
-    getLocalStorageField_(element);
-  }
-  // Registers the appropriate events for input elements.
-  if (element.type == 'checkbox') {
-    element.onclick = function() { storeLocalStorageField_(this); };
-  } else if (element.type == 'text') {
-    element.onblur = function() { storeLocalStorageField_(this); };
-  } else {
-    error('Unsupportered input type: ' + '\"' + element.type + '\"' );
+  if (request.readyState == 4 && request.status == 200) {
+    global.ourPeerId = parseOurPeerId_(request.responseText);
+    global.remotePeerId = parseRemotePeerIdIfConnected_(request.responseText);
+    startHangingGet_(global.serverUrl, global.ourPeerId);
+    print_('ok-connected');
   }
 }
 
-/**
- * Fetches the stored values from local storage and updates checkbox status.
- * @private
- * @param {!Object} element of which id is representing the key parameter for
- *     local storage.
- */
-function getLocalStorageField_(element) {
-  // Makes sure the checkbox status is matching the local storage value.
-  if (element.type == 'checkbox') {
-    element.checked = (localStorage.getItem(element.id) == 'true');
-  } else if (element.type == 'text' ) {
-    element.value = localStorage.getItem(element.id);
-  } else {
-    error('Unsupportered input type: ' + '\"' + element.type + '\"' );
+/** @private */
+function parseOurPeerId_(responseText) {

[kjellander_chromium, 2014/01/07 10:34:17]

I don't know why this is called ourPeerId and not localPeerId. Can you fix in a
future CL?

[jansson, 2014/01/07 15:49:39]

Adding to my todo!

+  // According to peerconnection_server's protocol.
+  var peerList = responseText.split('\n');
+  return parseInt(peerList[0].split(',')[1]);
+}
+
+/** @private */
+function parseRemotePeerIdIfConnected_(responseText) {
+  var peerList = responseText.split('\n');
+  if (peerList.length == 1) {
+    // No peers have connected yet - we'll get their id later in a notification.
+    return null;
+  }
+  var remotePeerId = null;
+  for (var i = 0; i < peerList.length; i++) {
+    if (peerList[i].length == 0)
+      continue;
+
+    var parsed = peerList[i].split(',');
+    var name = parsed[0];
+    var id = parsed[1];
+
+    if (id != global.ourPeerId) {
+      print_('Found remote peer with name ' + name + ', id ' +
+                id + ' when connecting.');
+
+      // There should be at most one remote peer in this test.
+      if (remotePeerId != null)
+        error_('Expected just one remote peer in this test: ' +
+               'found several.');
+
+      // Found a remote peer.
+      remotePeerId = id;
+    }
+  }
+  return remotePeerId;
+}
+
+/** @private */
+function startHangingGet_(server, ourId) {
+  if (isDisconnected_())
+    return;
+
+  hangingGetRequest = new XMLHttpRequest();
+  hangingGetRequest.onreadystatechange = function() {
+    hangingGetCallback_(hangingGetRequest, server, ourId);
+  };
+  hangingGetRequest.ontimeout = function() {
+    hangingGetTimeoutCallback_(hangingGetRequest, server, ourId);
+  };
+  callUrl = server + '/wait?peer_id=' + ourId;
+  print_('Sending ' + callUrl);
+  hangingGetRequest.open('GET', callUrl, true);
+  hangingGetRequest.send();
+}
+
+/** @private */
+function hangingGetCallback_(hangingGetRequest, server, ourId) {
+  if (hangingGetRequest.readyState != 4 || hangingGetRequest.status == 0) {
+    // Code 0 is not possible if the server actually responded. Ignore.
+    return;
+  }
+  if (hangingGetRequest.status != 200) {
+    error_('Error ' + hangingGetRequest.status + ' from server: ' +
+           hangingGetRequest.statusText);
+  }
+  var targetId = readResponseHeader_(hangingGetRequest, 'Pragma');
+  if (targetId == ourId)
+    handleServerNotification_(hangingGetRequest.responseText);
+  else
+    handlePeerMessage_(targetId, hangingGetRequest.responseText);
+
+  hangingGetRequest.abort();
+  restartHangingGet_(server, ourId);
+}
+
+/** @private */
+function hangingGetTimeoutCallback_(hangingGetRequest, server, ourId) {
+  print_('Hanging GET times out, re-issuing...');
+  hangingGetRequest.abort();
+  restartHangingGet_(server, ourId);
+}
+
+/** @private */
+function handleServerNotification_(message) {
+  var parsed = message.split(',');
+  if (parseInt(parsed[2]) == 1) {
+    // Peer connected - this must be our remote peer, and it must mean we
+    // connected before them (except if we happened to connect to the server
+    // at precisely the same moment).
+    print_('Found remote peer with name ' + parsed[0] + ', id ' + parsed[1] +
+           ' when connecting.');
+    global.remotePeerId = parseInt(parsed[1]);
   }
 }
 
-/**
- * Stores the string value of the element object using local storage.
- * @private
- * @param {!Object} element of which id is representing the key parameter for
- *     local storage.
- */
-function storeLocalStorageField_(element) {
-  if (element.type == 'checkbox') {
-    localStorage.setItem(element.id, element.checked);
-  } else if (element.type == 'text') {
-    localStorage.setItem(element.id, element.value);
+/** @private */
+function closeCall_() {
+  if (global.peerConnection == null)
+    debug_('Closing call, but no call active.');
+  global.peerConnection.close();
+  global.peerConnection = null;
+}
+
+/** @private */
+function handlePeerMessage_(peerId, message) {
+  print_('Received message from peer ' + peerId + ': ' + message);
+  if (peerId != global.remotePeerId) {
+    error_('Received notification from unknown peer ' + peerId +
+           ' (only know about ' + global.remotePeerId + '.');
   }
+  if (message.search('BYE') == 0) {
+    print_('Received BYE from peer: closing call');
+    closeCall_();
+    return;
+  }
+  if (global.peerConnection == null && global.acceptsIncomingCalls) {
+    // The other side is calling us.
+    print_('We are being called: answer...');
+
+    global.peerConnection = createPeerConnection(STUN_SERVER,
+                                                 global.useRtpDataChannels);
+    if ($('auto-add-stream-oncall') &&
+        obtainGetUserMediaResult_() == 'ok-got-stream') {
+      print_('We have a local stream, so hook it up automatically.');
+      addLocalStreamToPeerConnection(global.peerConnection);
+    }
+    answerCall(global.peerConnection, message);
+    return;
+  }
+  handleMessage(global.peerConnection, message);
 }
+
+/** @private */
+function restartHangingGet_(server, ourId) {
+  window.setTimeout(function() {
+    startHangingGet_(server, ourId);
+  }, 0);
+}
+
+/** @private */
+function readResponseHeader_(request, key) {
+  var value = request.getResponseHeader(key);
+  if (value == null || value.length == 0) {
+    error_('Received empty value ' + value +
+           ' for response header key ' + key + '.');
+  }
+  return parseInt(value);
+}