Speeding up TwoGetUserMediaAndStop WebRTC test

content/test/data/media/webrtc_test_utilities.js

Index: content/test/data/media/webrtc_test_utilities.js
diff --git a/content/test/data/media/webrtc_test_utilities.js b/content/test/data/media/webrtc_test_utilities.js
index 02aac59b325d27b8711e000f03a5027db4f52243..0f8f0a947da5e9814d1528698cd77195ddc47ee3 100644
--- a/content/test/data/media/webrtc_test_utilities.js
+++ b/content/test/data/media/webrtc_test_utilities.js
@@ -113,7 +113,8 @@ function waitForBlackVideo(videoElement) {
 // Calculates the current frame rate and compares to |expected_frame_rate|
 // |callback| is triggered with value |true| if the calculated frame rate
 // is +-1 the expected or |false| if five calculations fail to match
-// |expected_frame_rate|.
+// |expected_frame_rate|. Calls back with OK if the check passed, otherwise
+// an error message.
 function validateFrameRate(videoElementName, expected_frame_rate, callback) {
   var videoElement = $(videoElementName);
   var startTime = new Date().getTime();
@@ -140,10 +141,11 @@ function validateFrameRate(videoElementName, expected_frame_rate, callback) {
     console.log('FrameRate in ' + videoElementName + ' is ' + fps);
     if (fps < expected_frame_rate + 1  && fps > expected_frame_rate - 1) {
       clearInterval(waitVideo);
-      callback(true);
+      callback('OK');
     } else if (attempts == 5) {
       clearInterval(waitVideo);
-      callback(false);
+      callback('Expected frame rate ' + expected_frame_rate + ' for ' +
+               'element ' + videoElementName + ', but got ' + fps);
     }
   }, 1000);
 }