1. Open the console panel, and enable "Show Chrome Errors".
2. Enter 'window.open("http://example.com/");' into the command line, and navigate back to this page.
3. Hover your mouse over the resulting window object.
4. An error will be thrown, saying:
   <http://example.com> was denied reading the property Window.nodeType from <http://example.net>.
uncaught exception: [Exception... "Illegal operation on WrappedNative prototype object" nsresult: "0x8057000c (NS_ERROR_XPC_BAD_OP_ON_WN_PROTO)" location: "native frame :: <unknown filename> :: <TOP_LEVEL> :: line 0" data: no]