warning_ and error_ functions are now wired to onunmute and onmute events

chrome/test/data/webrtc/manual/peerconnection_manual.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.
  */
 
  /**
  * 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
@@ skipping 898 matching lines @@
   print_(gRequestWebcamAndMicrophoneResult);
 }
 
 /** @private */
 function success_(method) {
   $('messages').innerHTML += '<span style="color:green;">' + method +
                              '(): success. </span><br>';
 }
 
 /** @private */
+function warning_(message) {

[mcasas, 2014/08/21 10:53:17]

It seems that there are:
- function print_(message)
- function debug_(message)
- function error_(message)
  (these three around l.1143
- function warning_(message)
- function failure_(method, error)

and they are all very similar. Could you bring them together and consolidate the
common parts?

+  $('debug').innerHTML += '<span style="color:orange;">' + message +
+                          '</span><br>';
+}
+
+/** @private */
 function failure_(method, error) {
   error_(method + '() failed: ' + JSON.stringify(error));
 }
 
 /** @private */
 function iceCallback_(event) {
   if (event.candidate)
     sendToPeer(global.remotePeerId, JSON.stringify(event.candidate));
 }
 
@@ skipping 71 matching lines @@
     window.addEventListener('loadedmetadata', function() {
         displayVideoSize_(videoTag);}, true);
 
     // Throw an error when no video is sent from camera but gUM returns OK.
     stream.getVideoTracks()[0].onended = function() {
       error_(global.localStream + ' getUserMedia successful but ' +
              'MediaStreamTrack.onended event fired, no frames from camera.');
     };
 
     // Print information on track going to mute or back from it.
-    // TODO(mcasas): add a warning_() function and move the following print_()
-    // notifications to error_() and warning_(), respectively.
     stream.getVideoTracks()[0].onmute = function() {
-      print_(global.localStream + ' track onmute event has fired');
+      error_(global.localStream + ' MediaStreamTrack.onmute event has fired, ' +
+             'no frames to the track.');
     };
     stream.getVideoTracks()[0].onunmute = function() {
-      print_(global.localStream + ' track onunmute event has fired');
+      warning_(global.localStream + ' MediaStreamTrack.onunmute event has ' +
+               'fired.');
     };
   }
 }
 
 /**
  * @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) {
@@ skipping 374 matching lines @@
 
 /** @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);
 }