Adjust line height for GoogleChrome

Window height is 630px and there are 42 lines, include cmdline.
Each lines' height should be 15px but it's not in GoogleChrome.

This will fix that.

![lh](https://f.cloud.github.com/assets/377137/1734122/1d1979f2-6342-11e3-8d40-88c59d785878.png)