title: iframe not reading cookies in Chrome
body: <p><strong>Chrome is not allowing a child iframe to read its own cookies.</strong></p>
  
  <p>I have a parent webpage with a child iframe:</p>
  
  <ul>
  <li>parent at <code>https://first-site.com</code></li>
  <li>child at <code>&lt;iframe src="https://second-site.com"&gt;</code> (inside of parent)</li>
  <li>cookie set with
  
  <ul>
  <li>path: '/'</li>
  <li>secure: true</li>
  <li>httpOnly: false</li>
  <li>domain: '.second-site.com'</li>
  </ul></li>
  </ul>
  
  <p>I control both sites, and I want the iframe to perform an operation within the iframe that requires reading cookies for <code>.second-site.com</code>. The outer parent doesn't need to know anything about this.</p>
  
  <p><strong>It works in all browsers except for Chrome.</strong></p>
  
  <p>Chrome is simply not making the child page's own cookies available to the child.</p>
  
  <p>Visiting the child page in its own window and performing the operation works in all browsers, including Chrome.</p>
  
  <p>I've tried both of these options in all permutations:</p>
  
  <ul>
  <li>Set <code>secure:false</code> or <code>secure:true</code> for the cookie</li>
  <li>Set <code>sandbox="allow-same-origin allow-scripts"</code> for the iframe, or remove the <code>sandbox</code> attribute</li>
  </ul>
  
  <p>What is Chrome doing differently, and how can an iframe in Chrome access its own cookies?</p>