Build fix after r130135. Dromaeo tests only report single memory value,

and computeStatistics should report variance as 0 in such cases.

* resources/runner.js:


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@130181 268f45cc-cd09-0410-ab3c-d52691b4dbfc

PerformanceTests/ChangeLog

+2012-10-02  Ryosuke Niwa  <rniwa@webkit.org>
+
+        Build fix after r130135. Dromaeo tests only report single memory value,
+        and computeStatistics should report variance as 0 in such cases.
+
+        * resources/runner.js:
+
 2012-10-02  Philip Rogers  <pdr@google.com>
 
         Fix PerfTest standard deviation calculation.

PerformanceTests/resources/runner.js

@@ -80,7 +80,7 @@ if (window.testRunner) {
             result.mean += delta / sweep;
             squareSum += delta * (x - result.mean);
         }
-        result.variance = squareSum / (data.length - 1);
+        result.variance = data.length <= 1 ? 0 : squareSum / (data.length - 1);
         result.stdev = Math.sqrt(result.variance);
         result.unit = unit || "ms";