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

third_party/WebKit/LayoutTests/fast/canvas/script-tests/canvas-transparency-and-composite.js

-description("Series of tests to ensure correct behaviour of composite on a fully transparent color.");
-var ctx = document.createElement('canvas').getContext('2d');
-
-ctx.globalCompositeOperation = "source-over";
-ctx.fillStyle = 'rgba(0,0,0,0)';
-ctx.fillRect(0,0,100,100);
-
-ctx.save();
-ctx.translate(0,100);
-ctx.scale(1,-1);
-ctx.fillStyle = 'green';
-ctx.fillRect(0,0,100,100);
-ctx.restore();
-
-var imageData = ctx.getImageData(1, 1, 98, 98);
-var imgdata = imageData.data;
-shouldBe("imgdata[4]", "0");
-shouldBe("imgdata[5]", "128");
-shouldBe("imgdata[6]", "0");