Window atttributes for timing info

Hello,
    I am writing to seek interest of adding a set of window attributes in
the html5 specs
to let browser expose timing-related information of a page.

   Many web pages/apps these days use javascript to measure component/page
latencies. Some
open source project has also been trying to make it easier for web apps
authors to collect these
performance stats, one example is Jiffy (http://code.google.com/p/jiffy-web/)
presented in last year's
Velocity conference. All these apps will benefit if the browser can expose
some timing-related info
through some attributes of the window object. For example, window.[foo] to
give the elapse time
since the page transition.

    I will be happy to draft the specs for comments if there is interest.

cheers,
Z