chrome scaling problem

[dudiq]

1. go to http://ace.ajax.org/build/kitchen-sink.html
2. type a lot of text for getting vertical scroll
3. scroll to bottom
4. change scale of tab

and you can see, that we have small scrolling to top and in some scales(110% for example) have strange behavior with cursor position

win7 x64, chrome 17.0.963.83. m

[nightwing]

chrome started to use fractional line heights depending on zoom level

el.style.height = '15px'
el.getBoundingClientRect().height // 14.7888..

probably this is a bug in chrome, but
using getBoundingClientRect in text layer's $measureSizes fixes it

[nightwing]

fixed in b0bbb36 (cc #870)