title: Angular Material md-toolbar not sticking (md-scroll-shrink)
body: <p>I'm using a <code>&lt;md-subheader md-scroll-shrink&gt;</code> on my page, but it's not sticking to the top when the user scrolls down (like in the <a href="https://material.angularjs.org/latest/demo/toolbar" rel="nofollow">scroll shrink demo</a>).</p>
  
  <p>Any ideas? Maybe my layout is causing the problem?</p>
  
  <pre><code>&lt;body&gt;
    &lt;div&gt;
      &lt;md-toolbar md-scroll-shrink&gt;
      &lt;div&gt;
        &lt;md-sidenav&gt;
        &lt;md-content&gt;
          &lt;section&gt;
            &lt;md-subheader&gt;
  ...
  </code></pre>
  
  <p>Here is a <a href="http://codepen.io/lebolo/pen/KzmZbB" rel="nofollow">codepen</a>.</p>