LayoutTests/fast/text/emphasis-combined-text.html

<meta charset="utf-8">
<style>
html {
    -webkit-writing-mode: vertical-rl;
}

p {
    font-family: "hiragino mincho pron";
    font-size: 48px;
}

.combine {
    -webkit-text-combine: horizontal;
}

</style>
<p>
    <span  style="-webkit-text-emphasis: sesame red">文字<span class="combine">900</span>年</span>
</p>
<p>
    <span  style="-webkit-text-emphasis: '@' red">文字<span class="combine">900</span>年</span>
</p>
<p>
    <span  style="-webkit-text-emphasis: '年' red">文字<span class="combine">900</span>年</span>
</p>