title: flex child is growing out of parent
body: <p>How to force the green boxes to be contained in the red one without setting a static height value and no absolute position?</p>
  
  <p>I want to shrink the content to fit into the parent.</p>
  
  <p>The content (video in this case) is allowed to shrink and scrollbars are allowed.</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-css lang-css prettyprint-override"><code>.my-box {
    height: 300px;
    width: 600px;
    background: red;
    padding: 5px;
  }
  .content-box {
    background: blue;
  }
  .col {
    display: flex;
    flex-direction: column;
    justify-content: space-between
  }
  .box-shrink {
    flex: 0 1 auto;
    background: green;
    padding: 5px;
    margin: 5px;
  }
  .box-grow {
    flex: 1 0 auto;
    background: green;
    padding: 5px;
    margin: 5px;
  }
  video {
    max-height: 100%;
    max-width: 100%;
    margin: auto;
    display: block;
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;div class="my-box col"&gt;
    &lt;div class="box-shrink"&gt;
      small sized static content
    &lt;/div&gt;
    &lt;div class="content-box box-grow"&gt;
      &lt;video controls&gt;
        &lt;source src="http://techslides.com/demos/sample-videos/small.webm" type="video/webm"&gt;
      &lt;/video&gt;
    &lt;/div&gt;
    &lt;div class="box-shrink"&gt;
      small sized static content
    &lt;/div&gt;
  &lt;/div&gt;</code></pre>
  </div>
  </div>
  </p>