Robot: support testing subdomains

[haysmark]

Under default browser x-domain policy, the robot can't test a page, for instance, on www.dojotoolkit.org, if the test file lives on archive.dojotoolkit.org. In particular, if you are testing an app that navigates across subdomains like these, the browser throws a Permission Denied error and the robot simply stops working.

The DOM Level 1 spec has a standard attribute called document.domain that is designed to let you get around this limitation for pages on the same superdomain (dojotoolkit.org). But because the robot uses an iframe to load the applet environment, no one tells the iframe about the document.domain change, so you still see Permission Denied errors.

We could very easily enhance the robot to propagate this standard variable to the iframe. In doing so, we would gain support for testing more structurally complex apps that pull in data from servers living on other subdomains.

[haysmark]

Fixes #9016. Add support for document.domain to the doh.robot.

[haysmark]

Attached prototype fix.

[bill]

Is there a reason this needs to go into 1.3.1 instead of 1.4? 1.3.1 is only for critical bugs.

[Douglas Hays]

(In [17476]) Fixes #9016. Proxy commit for haysmark. Add support to the doh.robot for user-specified document.domain.