samplecode: Remove duplicated include of SkWindow.h from SampleApp.h
samplecode: Remove duplicated include of SkWindow.h from SampleApp.h

R=epoger@google.com

Review URL: https://codereview.appspot.com/6566051

git-svn-id: e8541e15acce502a64c929015570ad1648e548cd@5737 2bbb7eff-a529-9590-31e7-b0007b416f81

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