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chromium/third_party/blink/web_tests/wpt_internal/printing/scaling-001-print-ref.html 

<!DOCTYPE html>
<script>
  if (window.testRunner) {
    testRunner.setPrintingScaleFactor(1);
  }
</script>
<style>
  body {
    margin: 0;
  }
</style>
<div style="scale:2; transform-origin:top left; width:50%; height:50vh; background:yellow;">
  This page should be all yellow.
</div>
<div style="break-before:page; scale:2; transform-origin:top left; width:50%; height:50vh; background:orange;">
  This page should be all orange.
</div>