[Merge M-57] Add a warning for the deprecation of content-initiated data URL navigations

third_party/WebKit/LayoutTests/http/tests/security/popup-allowed-by-sandbox-when-allowed.html

 <script>
 if (window.testRunner) {
     testRunner.dumpAsText();
     testRunner.waitUntilDone();
     testRunner.setCanOpenWindows(true);
     testRunner.setCloseRemainingWindowsWhenComplete(true);
 }
 </script>
 <p>To run this test outside of DumpRenderTree, please disable your popup blocker!</p>
-<iframe sandbox="allow-scripts allow-popups"
+<iframe sandbox="allow-scripts allow-popups allow-same-origin"
   src="data:text/html,
        <script>
-       var win = window.open('data:text/html,<script>if (window.testRunner) testRunner.notifyDone();<\/script>', '_blank');
-       console.log(win ? 'PASS' : 'FAIL');
+       var win = window.open('about:blank', '_blank');
+       if (win) {
+         console.log('PASS');
+         win.document.write(
+           '<script>if (window.testRunner) testRunner.notifyDone();<\/script>');
+       } else {
+         console.log('FAIL');
+         if (window.testRunner) testRunner.notifyDone();
+       }
        </script>"
   ></iframe>