Make canvas perf tests run less than 6 sec.

PerformanceTests/Canvas/resources/canvas_runner.js

+// CanvasRunner is a wrapper of PerformanceTests/resources/runner.js for canvas tests.
+(function () {
+    var MEASURE_DRAW_TIMES = 50;
+    var MAX_MEASURE_DRAW_TIMES = 1000;
+    var MAX_MEASURE_TIME_PER_FRAME = 1000; // 1 sec
+    var currentTest = null;
+
+    var CanvasRunner = {};
+
+    CanvasRunner.start = function (test) {
+        PerfTestRunner.prepareToMeasureValuesAsync({unit: 'runs/s',
+            description: test.description});
+        if (!test.doRun) {
+            CanvasRunner.logFatalError("\ndoRun must be set.\n");
+            return;
+        }
+        currentTest = test;
+        runTest();
+    }
+
+    function runTest() {
+        if (currentTest.preRun)
+            currentTest.preRun();
+
+        var start = PerfTestRunner.now();
+        var count = 0;
+        while ((PerfTestRunner.now() - start <= MAX_MEASURE_TIME_PER_FRAME) && (count * MEASURE_DRAW_TIMES < MAX_MEASURE_DRAW_TIMES)) {
+            for (var i = 0; i < MEASURE_DRAW_TIMES; i++) {
+                currentTest.doRun();
+            }
+            count++;
+        }
+        if (currentTest.ensureComplete)
+            currentTest.ensureComplete();
+        var elapsedTime = PerfTestRunner.now() - start;
+        if (currentTest.postRun)
+            currentTest.postRun();
+
+        PerfTestRunner.measureValueAsync(MEASURE_DRAW_TIMES * count * 1000 / elapsedTime);
+
+        requestAnimationFrame(runTest);
+    }
+
+    CanvasRunner.logFatalError = function (text) {
+        PerfTestRunner.logFatalError(text);
+    }
+
+    window.CanvasRunner = CanvasRunner;
+})();