LayoutTests/fast/forms/content-with-margins-inside-button.html

<style>
  div {
    width:100px;
    border: 1px solid;
    margin-top: 100px;
    margin-bottom: 100px;
  }
  
  button { float:left; margin:0; background-color: #cccccc; border:1px solid black; padding:0; font-family: Times; font-size:16px }
</style>

<button><div>Content</div></button>