chromium/chrome/browser/resources/privacy_sandbox/privacy_sandbox_privacy_policy_step.html

<style include="cr-shared-style shared-style">
  .iframe-content {
    border-color: var(--scrollable-border-color);
    border-style: solid;
    border-width: 1px 0;
    height: calc(100vh - var(--privacy-sandbox-dialog-buttons-row-height) - 2px);
    width: 100%;
  }
</style>

<iframe class="iframe-content" frameBorder="0"
src="chrome-untrusted://privacy-sandbox-dialog/privacy-policy"></iframe>