child-src and frame-src CSP are not applicable when navigating a new window.

third_party/WebKit/LayoutTests/http/tests/navigation/post-with-modifier.html

 <div id="container">
 <p>You should run this test in Test Runner</p>
 <form method="post" action="resources/post-with-modifier.php">
     <input type="hidden" name="a" value="b">
     <input type="submit">
 </form>
 </div>
 <div id="console"></div>
 <script src="/js-test-resources/js-test.js"></script>
 <script>
@@ skipping 16 matching lines @@
     window.onload = function() {
         var submit = document.querySelector('input[type="submit"]');
         eventSender.dragMode = false;
         eventSender.mouseMoveTo(submit.offsetLeft + 3, submit.offsetTop + 3);
         eventSender.mouseDown(0);
         eventSender.mouseUp(0, ['shiftKey']);
     };
 
     // Shift-clicking doesn't set window.opener, so we allow the new window
     // to find the opener using the name being set below.
+    // TODO(lukasza): After fixing https://crbug.com/658386, the test will
+    // need to use another mechanism for communicating verification results
+    // (most likely OOPIF-replicated testRunner.setCustomTextOutput).
     window.name = "mainTestWindow";
     window.addEventListener('message', function(e) {
         concludeTest(e.data);
     });
 }
 </script>