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

third_party/WebKit/LayoutTests/fast/canvas/script-tests/canvas-stroke-zeroSizeGradient.js

-description("Series of tests to ensure that stroke() paints nothing on canvas when the strokeStyle is set to a zero-size gradient.");
-var ctx = document.createElement('canvas').getContext('2d');
-
-ctx.fillStyle = '#0f0';
-ctx.fillRect(0, 0, 1, 1);
-
-var g = ctx.createLinearGradient(0, 0, 0, 0); // zero-length line (undefined direction);
-g.addColorStop(0, '#f00');
-g.addColorStop(1, '#f00');
-ctx.strokeStyle = g;
-ctx.rect(0, 0, 1 ,1);
-ctx.stroke();
-
-var imageData = ctx.getImageData(0, 0, 1, 1);
-var imgdata = imageData.data;
-shouldBe("imgdata[0]", "0");
-shouldBe("imgdata[1]", "255");
-shouldBe("imgdata[2]", "0");