Open the attached test case page. The browser correctly sizes the body element when the scaled-up div is shown (and when a non-scaled div is shown, though that's not included) but it does not properly size the body element when the scaled-down div is shown. In that case, the body element should be ~1024px in height, but it's 2026px. This results in a bunch of extra whitespace at the bottom of the page.
Bug occurs in:
* WebKit nightly (Version 6.0.2 (7536.26.17, 537+))
* Chrome Canary (Version 27.0.1412.0 canary)
* Firefox Beta (19.0) - I'll be filing a bug against Firefox as well
Only tested on OS X 10.7.5.
Created attachment 188445 [details]
Simplified test case
Attempting to add attachment, since it didn't work during creation.
Filed against Firefox as https://bugzilla.mozilla.org/show_bug.cgi?id=841596.
Closing per the comment at https://bugzilla.mozilla.org/show_bug.cgi?id=841596#c2.
Note that this test case does not exhibit the bug if height:100% is set on the body (see forthcoming attachment as example).
Created attachment 188461 [details]
Test case, with body height:100% addition
Transforms don't affect layout. The body is being sized before the transform is applied. However, transforms do affect overflow, so with the 2x div, the scrollbars allow you to scroll to the bottom. This is correct behavior.