chromium/chrome/browser/resources/chromeos/healthd_internals/line_chart/line_chart.html

<style include="healthd-internals-shared">
  #chartRoot {
    background-color: var(--cros-ref-neutral90);
    display: flex;
    flex-direction: row;
    height: 90%;
    overflow: hidden;
    width: 90%;
    margin: 0 auto;
  }

  #canvasContainer {
    flex-grow: 1;
    touch-action: none;
  }

  #mainCanvas {
    background-color: var(--cros-ref-neutral90);
    touch-action: none;
  }
</style>
<div id="chartRoot">
  <healthd-internals-line-chart-menu id="chartMenu">
  </healthd-internals-line-chart-menu>
  <div id="canvasContainer">
    <canvas id="mainCanvas"></canvas>
    <healthd-internals-line-chart-scrollbar id="chartScrollbar">
    </healthd-internals-line-chart-scrollbar>
  </div>
</div>