chromium/third_party/blink/web_tests/fast/canvas/canvas-toDataURL-bitmaprenderer.html

<script src="../../resources/testharness.js"></script>
<script src="../../resources/testharnessreport.js"></script>

<script>

async_test(function(t) {
	var magentaPixelImg = document.createElement('img');
	// This is a base64 encoded string representing a single magenta pixel
	magentaPixelImg.src = "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mP8z/D/PwAHAwL/qGeMxAAAAABJRU5ErkJggg==";
	magentaPixelImg.onload = () => {
	  createImageBitmap(magentaPixelImg,0,0,magentaPixelImg.naturalWidth,magentaPixelImg.naturalHeight).then((image) => {
		const can = document.createElement('canvas');
	    const ctx = can.getContext('bitmaprenderer');
		const can2 = document.createElement('canvas');
		can2.width = image.width;
		can2.height = image.height;
	    const ctx2 = can2.getContext('2d', {willReadFrequently: true});
	    ctx.transferFromImageBitmap(image);
		ctx2.drawImage(magentaPixelImg, 0, 0);
        t.step(() => {
	      assert_equals(can.toDataURL(), can2.toDataURL());
		});
		t.done();
	  });
	}
}, "Test that canvas toDataURL returns the same URL that was expected when the canvas is of bitmaprenderer type.")

</script>