Make canvas perf tests run less than 6 sec.

PerformanceTests/Canvas/draw-dynamic-canvas-2d-to-hw-accelerated-canvas-2d.html

Index: PerformanceTests/Canvas/draw-dynamic-canvas-2d-to-hw-accelerated-canvas-2d.html
diff --git a/PerformanceTests/Canvas/draw-dynamic-canvas-2d-to-hw-accelerated-canvas-2d.html b/PerformanceTests/Canvas/draw-dynamic-canvas-2d-to-hw-accelerated-canvas-2d.html
index a913cb45e9748f0efa630003a59d971e16302458..b7d8ef9f5eb3210d5ac7fa26d597e82a3c09077a 100644
--- a/PerformanceTests/Canvas/draw-dynamic-canvas-2d-to-hw-accelerated-canvas-2d.html
+++ b/PerformanceTests/Canvas/draw-dynamic-canvas-2d-to-hw-accelerated-canvas-2d.html
@@ -7,9 +7,9 @@ var sourceCanvas2D = document.createElement("canvas");
 var sourceCtx2D = sourceCanvas2D.getContext("2d");
 var destCanvas2D = document.createElement("canvas");
 var destCtx2D = destCanvas2D.getContext("2d");
-var MEASURE_DRAW_TIMES = 1000;
-var MAX_COUNT = 60000;
-var count = 0;
+var MEASURE_DRAW_TIMES = 50;
+var MAX_MEASURE_DRAW_TIMES = 1000;
+var MAX_MEASURE_TIME_PER_FRAME = 1000; // 1 sec
  
 function setSize(sourceWidth, sourceHeight, destWidth, destHeight) {
     sourceCanvas2D.width = sourceWidth;
@@ -29,24 +29,26 @@ function fillCanvas(ctx2d, canvas2d) {
 
 function drawCanvas2DToCanvas2D() {
     var start = PerfTestRunner.now();
-    for (var i = 0; i < MEASURE_DRAW_TIMES; i++) {
-        fillCanvas(sourceCtx2D, sourceCanvas2D);
-        // draw dynamic Canvas
-        destCtx2D.drawImage(sourceCanvas2D, 0, 0);
+    var count = 0;
+    while ((PerfTestRunner.now() - start <= MAX_MEASURE_TIME_PER_FRAME) && (count * MEASURE_DRAW_TIMES < MAX_MEASURE_DRAW_TIMES)) {

[Ken Russell (switch to Gerrit), 2014/03/17 06:03:24]

The duplicated constants and harness code throughout these six benchmarks is
unfortunate. Can you please think of a way to share code between them (perhaps
moving the harness to a separate .js file and passing in an instance of a
constructor function with setup, run, and teardown functions on its prototype)
so that in the future any changes can be made in one place?

+        for (var i = 0; i < MEASURE_DRAW_TIMES; i++) {
+            fillCanvas(sourceCtx2D, sourceCanvas2D);
+            // draw dynamic Canvas
+            destCtx2D.drawImage(sourceCanvas2D, 0, 0);
+        }
+        count++;
     }
     // Calling getImageData() is just to flush out the content when
     // accelerated 2D canvas is in use. The cost of reading 1x1 pixels is low.
     destCtx2D.getImageData(0, 0, 1, 1);
-    count++;
 
     var elapsedTime = PerfTestRunner.now() - start;
-    PerfTestRunner.measureValueAsync(MEASURE_DRAW_TIMES * 1000 / elapsedTime);
-    if (count < MAX_COUNT)
-        requestAnimationFrame(drawCanvas2DToCanvas2D);
+    PerfTestRunner.measureValueAsync(MEASURE_DRAW_TIMES * count * 1000 / elapsedTime);
+
+    requestAnimationFrame(drawCanvas2DToCanvas2D);

[Ken Russell (switch to Gerrit), 2014/03/17 06:03:24]

Since the conditional on requestAnimationFrame was removed, how does this not go
into an infinite loop? Is this test required to run inside a test harness?
PerformanceTests/resources/runner.js seems to support both running inside
TestRunner and not.

 }
 
 function onCompletedRun() {
-    count = MAX_COUNT;
 }
 
 window.onload = function () {