Use testharness.js instead of js-test.js in LayoutTests/fast/canvas tests.

third_party/WebKit/LayoutTests/fast/canvas/script-tests/gradient-with-clip.js

-description("Test for canvas regression where gradient clips were not cleared https://bugs.webkit.org/show_bug.cgi?id=21498")
-
-function pixelValueAt(context, x, y) {
-    var imageData = context.getImageData(x, y, 1, 1);
-    return imageData.data;
-}
-
-function pixelToString(p) {
-    return "[" + p[0] + ", " + p[1] + ", " + p[2] + ", " + p[3] + "]"
-}
-
-function pixelShouldBe(context, x, y, expectedPixelString) {
-    var pixel = pixelValueAt(context, x, y);
-    var expectedPixel = eval(expectedPixelString);
-    
-    var pixelString = "pixel " + x + ", " + y;
-    if (areArraysEqual(pixel, expectedPixel)) {
-        testPassed(pixelString + " is " + pixelToString(pixel));
-    } else {
-        testFailed(pixelString + " should be " + pixelToString(expectedPixel) + " was " + pixelToString(pixel));
-    }
-}
-
-function fillWithColor(context, color) {
-    context.save();
-    context.fillStyle = color;
-    context.fillRect(0, 0, canvas.width, canvas.height);
-    context.restore();
-}
-
-var canvas = document.createElement("canvas");
-canvas.height = 100;
-canvas.width = 100;
-canvas.style.height = "100";
-canvas.style.width = "100";
-
-document.body.appendChild(canvas);
-
-var greenImage = document.createElement("canvas");
-greenImage.height = 10;
-greenImage.width = 10;
-var greenCtx = greenImage.getContext('2d');
-fillWithColor(greenCtx, "green");
-var greenPixel = pixelValueAt(greenCtx, 0, 0);
-
-
-var ctx = canvas.getContext('2d');
-var gradient = ctx.createLinearGradient(0, 0, 10, 0);
-gradient.addColorStop(0, "blue");
-gradient.addColorStop(1, "red");
-ctx.fillStyle = gradient;
-ctx.beginPath();
-ctx.moveTo(0, 0);
-ctx.lineTo(10, 5);
-ctx.lineTo(10, 10);
-ctx.lineTo(5, 10);
-ctx.closePath();
-ctx.fill();
-
-ctx.fillStyle = "green";
-ctx.fillRect(20, 20, 10, 10);
-
-pixelShouldBe(ctx, 20, 20, "greenPixel");