chromium/third_party/blink/web_tests/fast/shapes/shape-outside-floats/shape-outside-linear-gradient.html

<!DOCTYPE html>
<html>
<head>
<style>
#image-shape {
    float: left;
    shape-outside: linear-gradient(to right, rgba(0, 0, 255, 1), rgba(0, 0, 255, 0));
    shape-image-threshold: 0.75; /* use a bigger threshold than WK test because of Skia gradient rendering difference. */
    width: 100px;
    height: 100px;
}

#content {
    font: 50px/1 Ahem, sans-serif;
    width: 600px;
    color: green;
}
</style>
<div id="content">
  <div id="image-shape"></div>
  X<br>X<br>X
</div>
</body>
</html>