chromium/third_party/blink/web_tests/external/wpt/css/css-content/element-replacement.html

<!DOCTYPE html>
<title>The content CSS attribute can replace an element's contents</title>
<link rel="match" href="element-replacement-ref.html" />
<link rel="help" href="https://drafts.csswg.org/css-content-3/#content-property" />
<meta name="assert" content"This test checks that the CSS content propertly can replace a normal element's contents" />

<style>
p {
  margin: 0;
  content: url('resources/rect.svg');
}
</style>

<p>This text should not be visible</p>