LayoutTests/fast/writing-mode/margins.html

<style>
.container {
    position: relative;
    background-color: pink;
    outline: 1px solid black;
    display: inline-block;
}
.box {
    background-color: grey;
    width: 100px;
    height: 100px;
    margin: 10px 20px 30px 40px;
}
</style>

<div>The four boxes below should look identical.</div>

<div class="container">
    <div class="box" style="-webkit-writing-mode: horizontal-tb;"></div>
</div>

<div class="container">
    <div class="box" style="-webkit-writing-mode: horizontal-bt;"></div>
</div>

<div class="container">
    <div class="box" style="-webkit-writing-mode: vertical-lr;"></div>
</div>

<div class="container">
    <div class="box" style="-webkit-writing-mode: vertical-rl;"></div>
</div>