chromium/src/third_party/blink/web_tests/css3/filters/effect-grayscale-hw.html

<!-- This test uses a particular image size to avoid hitting flakiness in mesa texture sampling.  See http://crbug.com/621892 for more details. -->
<style>
img {
    will-change: transform;
}
div {
    width: 160px;
    height: 90px;
    overflow: hidden;
    display: inline-block;
}
</style>
<div><img style="filter: grayscale(0)" src="resources/reference_square.png"></div>
<div><img style="filter: grayscale(0.2)" src="resources/reference_square.png"></div>
<div><img style="filter: grayscale(0.4)" src="resources/reference_square.png"></div>
<div><img style="filter: grayscale(0.6)" src="resources/reference_square.png"></div>
<div><img style="filter: grayscale(0.8)" src="resources/reference_square.png"></div>
<div><img style="filter: grayscale(1.0)" src="resources/reference_square.png"></div>