Add text-rendering and font-smoothing to the font cache key.
Add text-rendering and font-smoothing to the font cache key.

The text-rendering enumeration is added to the key on all platforms
as it exists on all platforms. The font-smoothing enumeration is only
added on Mac as it is CoreGraphics specific. This change fixes several
odd issues with the use of font-smoothing on Mac where it sometimes
did not work, and other times appeared to leak.

This also cleans up the font cache key code a bit.

R=eae@chromium.org

Review URL: https://codereview.chromium.org/26919002

git-svn-id: bf5cd6ccde378db821296732a091cfbcf5285fbd@159494 bbb929c8-8fbe-4397-9dbb-9b2b20218538

smishenk/blink-crosswalk,hgl888/blink-crosswalk-efl,nwjs/blink,Bysmyyr/blink-crosswalk,ondra-novak/blink,nwjs/blink,Pluto-tv/blink-crosswalk,ondra-novak/blink,crosswalk-project/blink-crosswalk-efl,Pluto-tv/blink-crosswalk,XiaosongWei/blink-crosswalk,modulexcite/blink,XiaosongWei/blink-crosswalk,smishenk/blink-crosswalk,Pluto-tv/blink-crosswalk,modulexcite/blink,nwjs/blink,Bysmyyr/blink-crosswalk,nwjs/blink,Bysmyyr/blink-crosswalk,PeterWangIntel/blink-crosswalk,modulexcite/blink,smishenk/blink-crosswalk,XiaosongWei/blink-crosswalk,modulexcite/blink,nwjs/blink,PeterWangIntel/blink-crosswalk,XiaosongWei/blink-crosswalk,kurli/blink-crosswalk,modulexcite/blink,XiaosongWei/blink-crosswalk,ondra-novak/blink,PeterWangIntel/blink-crosswalk,hgl888/blink-crosswalk-efl,smishenk/blink-crosswalk,Pluto-tv/blink-crosswalk,hgl888/blink-crosswalk-efl,XiaosongWei/blink-crosswalk,ondra-novak/blink,nwjs/blink,crosswalk-project/blink-crosswalk-efl,PeterWangIntel/blink-crosswalk,nwjs/blink,crosswalk-project/blink-crosswalk-efl,ondra-novak/blink,modulexcite/blink,hgl888/blink-crosswalk-efl,jtg-gg/blink,kurli/blink-crosswalk,crosswalk-project/blink-crosswalk-efl,Pluto-tv/blink-crosswalk,smishenk/blink-crosswalk,jtg-gg/blink,crosswalk-project/blink-crosswalk-efl,hgl888/blink-crosswalk-efl,ondra-novak/blink,XiaosongWei/blink-crosswalk,kurli/blink-crosswalk,XiaosongWei/blink-crosswalk,Pluto-tv/blink-crosswalk,nwjs/blink,jtg-gg/blink,smishenk/blink-crosswalk,PeterWangIntel/blink-crosswalk,modulexcite/blink,smishenk/blink-crosswalk,PeterWangIntel/blink-crosswalk,crosswalk-project/blink-crosswalk-efl,smishenk/blink-crosswalk,Bysmyyr/blink-crosswalk,crosswalk-project/blink-crosswalk-efl,Bysmyyr/blink-crosswalk,smishenk/blink-crosswalk,ondra-novak/blink,Pluto-tv/blink-crosswalk,kurli/blink-crosswalk,modulexcite/blink,hgl888/blink-crosswalk-efl,kurli/blink-crosswalk,hgl888/blink-crosswalk-efl,PeterWangIntel/blink-crosswalk,jtg-gg/blink,hgl888/blink-crosswalk-efl,Bysmyyr/blink-crosswalk,ondra-novak/blink,PeterWangIntel/blink-crosswalk,XiaosongWei/blink-crosswalk,kurli/blink-crosswalk,PeterWangIntel/blink-crosswalk,hgl888/blink-crosswalk-efl,smishenk/blink-crosswalk,Bysmyyr/blink-crosswalk,modulexcite/blink,jtg-gg/blink,kurli/blink-crosswalk,modulexcite/blink,jtg-gg/blink,crosswalk-project/blink-crosswalk-efl,hgl888/blink-crosswalk-efl,jtg-gg/blink,crosswalk-project/blink-crosswalk-efl,PeterWangIntel/blink-crosswalk,kurli/blink-crosswalk,jtg-gg/blink,Bysmyyr/blink-crosswalk,Bysmyyr/blink-crosswalk,Bysmyyr/blink-crosswalk,kurli/blink-crosswalk,Pluto-tv/blink-crosswalk,XiaosongWei/blink-crosswalk,Pluto-tv/blink-crosswalk,nwjs/blink,kurli/blink-crosswalk,ondra-novak/blink,nwjs/blink,jtg-gg/blink,jtg-gg/blink,Pluto-tv/blink-crosswalk