move SkAutoGraphics into SkGraphics.h add [] operators to SkString git-svn-id: http://skia.googlecode.com/svn/trunk@228 2bbb7eff-a529-9590-31e7-b0007b416f81
git-svn-id: http://skia.googlecode.com/svn/trunk@227 2bbb7eff-a529-9590-31e7-b0007b416f81