page_displays_insecure_content_in_iframe.html

<html>
  <head><title>Page that displays insecure content in an iframe</title></head>
  <body>
    This page contains an iframe which loads an image over an http connection,
    causing insecure content (when this page is loaded over https).<br>
    <iframe src="https://REPLACE_WITH_HOST_AND_PORT/ssl/page_displays_insecure_content.html"/>
  </body>
</html>

chromium/chrome/test/data/ssl/page_displays_insecure_content_in_iframe.html