skia: Always use aliased text when antialiasing is disabled.

skia: Always use aliased text when antialiasing is disabled.

Otherwise, people who have antialiasing disabled end up with
subpixel rendering if the subpixel setting happens to be set
to something other than "none".  This change's interpretation
of these overlapping settings seems to be consistent with
GTK's and Firefox's.

Patch-by: Dan Erat
Signed-off-by: Adam Langley
BUG=http://code.google.com/p/chromium/issues/detail?id=28382

http://codereview.appspot.com/186248

git-svn-id: http://skia.googlecode.com/svn/trunk@475 2bbb7eff-a529-9590-31e7-b0007b416f81