Limit zoom animation to a certain zoom level span

[mourner]

Doing a large zoom in chrome will result in that tab locking up.
Seems to me that sometimes Chrome can't hande CSS3 Transform Transition with a too big scale (so that animated area gets to a huge size in pixels).

[danzel]

Added some details in the description.

Here is a test case from @stewgeo to repro:
http://jsfiddle.net/VyrEt/4/
Screenshot of result in #1408