Throw exceptions on all failed cross-origin access checks.

Throw exceptions on all failed cross-origin access checks.

Rather than special-casing access to Location properties[1], we should
allow developers to safely swallow cross-origin access check failures by
throwing an exception upon access to potentially interesting properties.

For example, Firefox currently throws exceptions for cross-origin access
such as `window.parent.NaN` and `window.parent.history`. This patch
matches that behavior by throwing on access to Window properties and the
History object.

[1]: http://src.chromium.org/viewvc/blink?view=rev&rev=154564

BUG=17325, 237080
R=abarth@chromium.org

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=154747

[Mike West, 2013-07-22 08:44:28]

Hi Adam. This patch follows up on your suggestion in
https://codereview.chromium.org/19095003/#msg2 to extend cross-origin exception
throwing to all forms of failed access checks.

I poked a bit at Firefox nightly, and it seems safe for us to match their
current behavior of throwing on access to Window properties and the History
object. I haven't done an exhaustive check to make sure that we're matching
their behavior in all respects, but the spot checks I've made work correctly.

WDYT?

-mike

[abarth-chromium, 2013-07-22 17:47:52]

Code change LGTM.  I didn't review the changes to test expectations.

This change increases the compatibility risk, but I think it makes sense to be
consistent and to match Firefox.  If we run into compat trouble, we might need
to roll back this CL.

[Mike West, 2013-07-23 07:39:07]

On 2013/07/22 17:47:52, abarth wrote:
> Code change LGTM.  I didn't review the changes to test expectations.
> 
> This change increases the compatibility risk, but I think it makes sense to be
> consistent and to match Firefox.  If we run into compat trouble, we might need
> to roll back this CL.

You're right. We've still got a good amount of time before the next branch, so I
think landing this now is relatively low-risk. That said, I'll make sure to keep
an eye out for bug reports.

Thanks!

[commit-bot: I haz the power, 2013-07-23 09:28:56]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/mkwst@chromium.org/19932002/13001

[commit-bot: I haz the power, 2013-07-23 10:52:09]

Change committed as 154747