Adding lenient mode to WebRTC audio tests.

content/test/data/media/webrtc_test_audio.js

 // Copyright 2013 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.
 
 // Audio test utilities.
 
 // GetStats reports audio output energy in the [0, 32768] range.
 var MAX_AUDIO_OUTPUT_ENERGY = 32768;
 
 // Gathers |numSamples| samples at |frequency| number of times per second and
@@ skipping 11 matching lines @@
         callback(audioLevelSamples);
       }
     });
   }, 1000 / frequency);
 }
 
 // Tries to identify the beep-every-half-second signal generated by the fake
 // audio device in media/video/capture/fake_video_capture_device.cc. Fails the
 // test if we can't see a signal. The samples should have been gathered over at
 // least two seconds since we expect to see at least three "peaks" in there
-// (we should see either 3 or 4 depending on how things line up). We are quite
-// generous in what we consider to be a peak since Android devices in particular
-// seem to be flake-prone (they often don't reach anywhere near the max level
-// for some reason).
-function verifyAudioIsPlaying(samples) {
+// (we should see either 3 or 4 depending on how things line up).
+//
+// If |beLenient| is specified, we assume we're running on a slow device or
+// or under TSAN, and relax the checks quite a bit.
+function verifyAudioIsPlaying(samples, beLenient) {
   var numPeaks = 0;
-  var threshold = MAX_AUDIO_OUTPUT_ENERGY * 0.6;
+  var threshold = MAX_AUDIO_OUTPUT_ENERGY * 0.7;
+  if (beLenient)
+    threshold = MAX_AUDIO_OUTPUT_ENERGY * 0.6;
   var currentlyOverThreshold = false;
 
   // Detect when we have been been over the threshold and is going back again
   // (i.e. count peaks). We should see about one peak per second.
   for (var i = 0; i < samples.length; ++i) {
     if (currentlyOverThreshold && samples[i] < threshold)
       numPeaks++;
     currentlyOverThreshold = samples[i] >= threshold;
   }
 
   console.log('Number of peaks identified: ' + numPeaks);
 
-  if (numPeaks < 2)
-    failTest('Expected to see at least two peaks in audio signal, got ' +
-        numPeaks + '. Dumping samples for analysis: "' + samples + '"');
+  var expectedPeaks = 2;
+  if (beLenient)
+    expectedPeaks = 1;
+
+  if (numPeaks < expectedPeaks)
+    failTest('Expected to see at least ' + expectedPeaks + ' peak(s) in ' +
+        'audio signal, got ' + numPeaks + '. Dumping samples for analysis: "' +
+        samples + '"');
 }
 
 // If silent (like when muted), we should get very near zero audio level.
 function verifyIsSilent(samples) {
   var average = 0;
   for (var i = 0; i < samples.length; ++i)
     average += samples[i] / samples.length;
 
   console.log('Average audio level: ' + average);
   if (average > 500)
@@ skipping 10 matching lines @@
     var report = reports[i];
     if (report.names().indexOf('audioOutputLevel') != -1) {
       audioOutputLevels.push(report.stat('audioOutputLevel'));
     }
   }
   // Should only be one audio level reported, otherwise we get confused.
   assertEquals(1, audioOutputLevels.length);
 
   return audioOutputLevels[0];
 }