No-op window.prototype methods

Summary:
The refactor missed http://phabricator.khanacademy.org/D11241
This brings back the window.constructor no-oping.
We still have the sandbox attributes, as play-page wasn't in live-editor.

Test Plan: - Put this code in a program: https://gist.github.com/pamelafox/279929327eef347f5683 See nothing happen except println()s - no window.opens or alerts

Reviewers: john

Reviewed By: john

Subscribers: #cs

Differential Revision: http://phabricator.khanacademy.org/D13168