use canonical lfHeight so we can compare different LOGFONTs and map
equivalent fonts (except for height) to the same typeface. To do this I
add fSize to scale the output from GDI to get from the canonical int textSize
to the actual fractional size.
git-svn-id: http://skia.googlecode.com/svn/trunk@871 2bbb7eff-a529-9590-31e7-b0007b416f81
