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

R=epoger@google.com

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

git-svn-id: http://skia.googlecode.com/svn/trunk@5737 2bbb7eff-a529-9590-31e7-b0007b416f81
1 file changed