Prevent the memset16 ARM opt from failing when count is 0. Review URL: http://codereview.appspot.com/5639051
Prevent the memset16 ARM opt from failing when count is 0.
Review URL: http://codereview.appspot.com/5639051

git-svn-id: e8541e15acce502a64c929015570ad1648e548cd@3173 2bbb7eff-a529-9590-31e7-b0007b416f81

mrobinson/skia,Cue/skia,metajack/skia,mrobinson/skia,Cue/skia,Cue/skia,metajack/skia,metajack/skia,metajack/skia,mrobinson/skia,mrobinson/skia,Cue/skia,mrobinson/skia