Revert of Allow status = 0 when XHR is completed in Audit.loadFileFromUrl().

third_party/WebKit/LayoutTests/webaudio/resources/oscillator-testing.js

 // Notes about generated waveforms:
 //
 // QUESTION: Why does the wave shape not look like the exact shape (sharp edges)?
 // ANSWER: Because a shape with sharp edges has infinitely high frequency content.
 // Since a digital audio signal must be band-limited based on the nyquist frequency (half the sample-rate)
 // in order to avoid aliasing, this creates more rounded edges and "ringing" in the
 // appearance of the waveform.  See Nyquist-Shannon sampling theorem:
 // http://en.wikipedia.org/wiki/Nyquist%E2%80%93Shannon_sampling_theorem
 //
 // QUESTION: Why does the very end of the generated signal appear to get slightly weaker?
@@ skipping 25 matching lines @@
 
 // SNR must be greater than this to pass the test.
 // Q: Why is the SNR threshold not infinity?
 // A: The reference result is a 16-bit WAV file, so it won't compare exactly with the
 //    floating point result.
 var thresholdSNR = 10000;
 
 // Max diff must be less than this to pass the test.
 var thresholdDiff = 0;
 
+// Count the number of differences between the expected and actual result. The tests passes
+// if the count is less than this threshold.
+var thresholdDiffCount = 0;
+
 // Mostly for debugging
 
 // An AudioBuffer for the reference (expected) result.
 var reference = 0;
 
 // Signal power of the reference
 var signalPower = 0;
 
 // Noise power of the difference between the reference and actual result.
 var noisePower = 0;
@@ skipping 56 matching lines @@
     var diffCount = 0;
 
     for (var k = 0; k < renderedData.length; ++k) {
         var diff = renderedData[k] - reference[k];
         noisePower += diff * diff;
         signalPower += reference[k] * reference[k];
         if (Math.abs(diff) > maxError) {
             maxError = Math.abs(diff);
             errorPosition = k;
         }
+        // The reference file is a 16-bit WAV file, so we will almost never get an exact match
+        // between it and the actual floating-point result.
+        if (diff > 0) {
+            diffCount++;
+        }
     }
 
     var snr = calculateSNR(signalPower, noisePower);
     should(snr, "SNR")
         .beGreaterThanOrEqualTo(thresholdSNR);
     should(maxError, "Maximum difference")
         .beLessThanOrEqualTo(thresholdDiff);
 
+    should(diffCount,
+           "Number of differences between actual and expected result out of "
+           + renderedData.length + " frames")
+        .beLessThanOrEqualTo(thresholdDiffCount);
+
     var filename = "oscillator-" + oscType + "-actual.wav";
     if (downloadAudioBuffer(renderedBuffer, filename, true))
       should(true, "Saved reference file").message(filename, "");
 }
 
 function setThresholds(thresholds) {
     thresholdSNR = thresholds.snr;
     thresholdDiff = thresholds.maxDiff;
     thresholdDiffCount = thresholds.diffCount;
 }
 
 function runTest(context, oscType, description, task, should) {
   loadReferenceAndRunTest(context, oscType, task, should);
 }
 
 return {
     sampleRate: sampleRate,
     lengthInSeconds: lengthInSeconds,
     thresholdSNR: thresholdSNR,
     thresholdDiff: thresholdDiff,
+    thresholdDiffCount: thresholdDiffCount,
     waveScaleFactor: waveScaleFactor,
     setThresholds: setThresholds,
     runTest: runTest,
 };
 
 }());