Fixed video muting test on Android, added logging.

content/test/data/media/webrtc_test_utilities.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.
 
 // These must match with how the video and canvas tags are declared in html.
 const VIDEO_TAG_WIDTH = 320;
 const VIDEO_TAG_HEIGHT = 240;
 
 // Fake video capture background green is of value 135.
 const COLOR_BACKGROUND_GREEN = 135;
@@ skipping 19 matching lines @@
 
 function detectVideoStopped(videoElementName, callback) {
   detectVideo(videoElementName,
               function (pixels, previous_pixels) {
                 return !isVideoPlaying(pixels, previous_pixels);
               },
               callback);
 }
 
 function detectVideo(videoElementName, predicate, callback) {
+  console.log('Looking at video in element ' + videoElementName);
+
   var width = VIDEO_TAG_WIDTH;
   var height = VIDEO_TAG_HEIGHT;
   var videoElement = $(videoElementName);
   var canvas = $(videoElementName + '-canvas');
-  var old_pixels = [];
+  var oldPixels = [];
   var waitVideo = setInterval(function() {
     var context = canvas.getContext('2d');
     context.drawImage(videoElement, 0, 0, width, height);
     var pixels = context.getImageData(0, 0 , width, height / 3).data;
     // Check that there is an old and a new picture with the same size to
     // compare and use the function |predicate| to detect the video state in
     // that case.
-    if (old_pixels.length == pixels.length &&
-        predicate(pixels, old_pixels)) {
+    if (oldPixels.length == pixels.length &&
+        predicate(pixels, oldPixels)) {
+      console.log('Done looking at video in element ' + videoElementName);
       clearInterval(waitVideo);
       callback();
     }
-    old_pixels = pixels;
+    oldPixels = pixels;
   }, 200);
 }
 
 function waitForVideo(videoElement) {
   document.title = 'Waiting for video...';
   addExpectedEvent();
   detectVideoPlaying(videoElement, function () { eventOccured(); });
 }
 
 function waitForVideoToStop(videoElement) {
@@ skipping 17 matching lines @@
 
 function eventOccured() {
   ++gNumberOfEvents;
   if (gNumberOfEvents == gNumberOfExpectedEvents) {
     gAllEventsOccured();
   }
 }
 
 // This very basic video verification algorithm will be satisfied if any
 // pixels are changed.
-function isVideoPlaying(pixels, previous_pixels) {
+function isVideoPlaying(pixels, previousPixels) {
   for (var i = 0; i < pixels.length; i++) {
-    if (pixels[i] != previous_pixels[i]) {
+    if (pixels[i] != previousPixels[i]) {
       return true;
     }
   }
   return false;
 }
 
 // This function matches |left| and |right| and throws an exception if the
 // values don't match.
 function expectEquals(left, right) {
   if (left != right) {
@@ skipping 82 matching lines @@
         detectedAspectRatioString += " cropped";
       } else
         detectedAspectRatioString += " letterbox";
 
       console.log("Original image is: " + detectedAspectRatioString);
       callback(detectedAspectRatioString);
     }
   },
                               50);
 }