Tune performance test parameters.

LayoutTests/http/tests/perf/large-inlined-script.html

Index: LayoutTests/http/tests/perf/large-inlined-script.html
diff --git a/LayoutTests/http/tests/perf/large-inlined-script.html b/LayoutTests/http/tests/perf/large-inlined-script.html
index 794a68ce60d79425de20d5cbd7b8e41876ab537e..45a28f5ee0bf02377b7a7209625dd890a132229b 100644
--- a/LayoutTests/http/tests/perf/large-inlined-script.html
+++ b/LayoutTests/http/tests/perf/large-inlined-script.html
@@ -20,10 +20,10 @@ function test(magnitude, callback)
 Magnitude.description("This tests time complexity of parsing HTML with large inlined script.");
 Magnitude.initialExponent = 15;
 Magnitude.numPoints = 4;
-Magnitude.trim = 1;
-Magnitude.tolerance = 0.2;
-Magnitude.numTrials = 4;
-Magnitude.successThreshold = 0.5; // 2 out of 4
+Magnitude.trim = 0;
+Magnitude.tolerance = 0.33;
+Magnitude.numTrials = 5;
+Magnitude.successThreshold = 0.2; // 1 out of 5
 Magnitude.runAsync(setupFunction, test, Magnitude.LINEAR);
 </script>
 </head>