Add SK_API for SkData.  Needed for https://bugs.webkit.org/show_bug.cgi?id=91171
Add SK_API for SkData.  Needed for https://bugs.webkit.org/show_bug.cgi?id=91171

Review URL: https://codereview.appspot.com/6420047

git-svn-id: e8541e15acce502a64c929015570ad1648e548cd@4658 2bbb7eff-a529-9590-31e7-b0007b416f81

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