Require the entry document to have the same origin as the open()d document

third_party/WebKit/LayoutTests/fast/dom/HTMLDocument/document-open-return-value.html

Index: third_party/WebKit/LayoutTests/fast/dom/HTMLDocument/document-open-return-value.html
diff --git a/third_party/WebKit/LayoutTests/fast/dom/HTMLDocument/document-open-return-value.html b/third_party/WebKit/LayoutTests/fast/dom/HTMLDocument/document-open-return-value.html
index c76cf40d5d0510164e68e5d3e92d6eb2292da315..2a5cbed13b9726b67668672301cfb96064074a59 100644
--- a/third_party/WebKit/LayoutTests/fast/dom/HTMLDocument/document-open-return-value.html
+++ b/third_party/WebKit/LayoutTests/fast/dom/HTMLDocument/document-open-return-value.html
@@ -14,5 +14,5 @@ function test()
     document.getElementById("result").innerHTML = d.body.innerHTML;
 }
 </script>
-<iframe src="data:text/html,FAILURE"></iframe>

[jochen (gone - plz use gerrit), 2016/01/29 08:01:37]

data: will fail the canAccess() check. This test is about document.open()
returning a non-void result, so just changing the origin to about:blank makes
the test test what it's supposed to test again

[philipj_slow, 2016/01/29 08:39:18]

I guess that data: URLs in an <iframe> already have this behavior in Firefox? A
certain risk of regressions here, can you also check IE/Edge?

[jochen (gone - plz use gerrit), 2016/01/29 09:40:24]

no, data: is treated differently in chrome and firefox. Firefox treats data:
like about:blank (i.e. its origin is an alias to the containing document's
origin). In Chrome, data: is treated as a different origin. This test used to
only pass because of flags passed to layout tests to disable those security
checks. The test would fail when run in Chrome.

[philipj_slow, 2016/01/29 10:21:12]

Oh right, so this won't break sites that try to document.open their data:
iframes. Good.

+<iframe></iframe>
 </body>