chromium/third_party/blink/web_tests/external/wpt/css/css-flexbox/percentage-size-subitems-001.html

<!DOCTYPE html>
<meta charset="utf-8">
<title>CSS Flexbox Test: Percentage size on child of a flex item with margin, border, padding and scrollbar</title>
<link rel="author" title="Manuel Rego Casasnovas" href="mailto:[email protected]">
<link rel="help" href="https://drafts.csswg.org/css-flexbox-1/#flex-items">
<link rel="match" href="reference/percentage-size-subitems-001-ref.html">
<meta name="assert" content="Checks that flex items children resolve properly their percentage sizes, even when the flex item has margin, border, padding and scrollbar.">
<style>
.flex {
  display: inline-flex;
  border: solid 5px black;
  width: 150px;
  height: 100px;
  margin: 10px;
  vertical-align: top;
}

.item {
  flex: 1;
  overflow: scroll;
  border: solid magenta;
  border-width: 12px 9px 6px 3px;
  margin: 1px 2px 3px 4px;
  padding: 5px 15px 10px 20px;
  background: cyan;
}

.subitem {
  width: 100%;
  height: 100%;
  background: yellow;
}

.horizontalTB { writing-mode: horizontal-tb; }
.verticalLR { writing-mode: vertical-lr; }
.verticalRL {  writing-mode: vertical-rl; }
</style>

<p>The test passes if in the different examples you see scrollbars but there's no overflow, so you cannot actually scroll.</p>

<div class="flex">
  <div class="item horizontalTB">
    <div class="subitem"></div>
  </div>
</div>

<div class="flex">
  <div class="item horizontalTB">
    <div class="subitem verticalLR"></div>
  </div>
</div>

<div class="flex">
  <div class="item horizontalTB">
    <div class="subitem verticalRL"></div>
  </div>
</div>

<div class="flex">
  <div class="item verticalLR">
    <div class="subitem"></div>
  </div>
</div>

<div class="flex">
  <div class="item verticalLR">
    <div class="subitem horizontalTB"></div>
  </div>
</div>

<div class="flex">
  <div class="item verticalLR">
    <div class="subitem verticalRL"></div>
  </div>
</div>

<div class="flex">
  <div class="item verticalRL">
    <div class="subitem"></div>
  </div>
</div>

<div class="flex">
  <div class="item verticalRL">
    <div class="subitem horizontalTB"></div>
  </div>
</div>

<div class="flex">
  <div class="item verticalRL">
    <div class="subitem verticalLR"></div>
  </div>
</div>