chromium/third_party/blink/web_tests/virtual/text-antialias/international/complex-text-missing-glyph-fallback.html

<meta charset="utf-8">
<p>
 Verdana does not contain Japanese Hiragana glyphs,
 so the text should be drawn inside the parentheses below by falling back to the next font.
</p>
<p>[<span style="text-rendering:optimizeLegibility; font-family: Verdana, sans-serif; line-height: 16px;">あいうえお</span>]</p>
<p>
 Zero-width spaces should not be treated as missing glyphs.
</p>
<p>[<span style="font-family: Arial, Tahoma">&#x633;&zwnj;</span>]</p>
<p>[<span style="text-rendering:optimizeLegibility; font-family: Arial, Tahoma">AB&#8203;</span>]</p>