Codebase Browser
chromium
Go to App

chromium/third_party/blink/web_tests/http/tests/security/mixedContent/insecure-plugin-in-iframe.html 

<!DOCTYPE html>
<html>
<body>
<script>
if (window.testRunner) {
    testRunner.dumpAsText();
    testRunner.overridePreference("WebKitAllowRunningInsecureContent", true);
    testRunner.waitUntilDone();
}
</script>
<p>This test loads a secure iframe that loads an insecure plugin.  We should
get a mixed content callback because the insecure plugin can script the secure
origin.</p>
<iframe src="https://127.0.0.1:8443/security/mixedContent/resources/frame-with-insecure-plugin.html"></iframe>
</body>
</html>