ORKSkin: guard against nil window on ORKWidthForSignatureView()
ORKSkin: guard against nil window on ORKWidthForSignatureView()

YuanZhu-apple/ResearchKit,chb/ResearchKit,chb/ResearchKit,cornelltech/ResearchKit,DrGo/ResearchKit,umerkhan-apple/ResearchKit,md0u80c9/ResearchKit,danoli3/ResearchKit,cornelltech/ResearchKit,QuintilesRK/ResearchKit,jimmyti/ResearchKit,cornelltech/ResearchKit,jarrelscy/ResearchKit,oliverschaefer/ResearchKit,danoli3/ResearchKit,jeremiahyan/ResearchKit,allen7wang/ResearchKit,jimmyti/ResearchKit,oliverschaefer/ResearchKit,QuintilesRK/ResearchKit,weijentu/ResearchKit,md0u80c9/ResearchKit,boland25/ResearchKit,allen7wang/ResearchKit,allen7wang/ResearchKit,danoli3/ResearchKit,jarrelscy/ResearchKit,mluedke2/ResearchKit,umerkhan-apple/ResearchKit,KaiCode2/ResearchKit,jimmyti/ResearchKit,KaiCode2/ResearchKit,shazino/ResearchKit,mluedke2/ResearchKit,boland25/ResearchKit,YuanZhu-apple/ResearchKit,chb/ResearchKit,md0u80c9/ResearchKit,md0u80c9/ResearchKit,oliverschaefer/ResearchKit,DrGo/ResearchKit,shazino/ResearchKit,weijentu/ResearchKit,weijentu/ResearchKit,shazino/ResearchKit,mluedke2/ResearchKit,QuintilesRK/ResearchKit,jarrelscy/ResearchKit,chb/ResearchKit,YuanZhu-apple/ResearchKit,DrGo/ResearchKit,jeremiahyan/ResearchKit,boland25/ResearchKit,jeremiahyan/ResearchKit,YuanZhu-apple/ResearchKit,oliverschaefer/ResearchKit,boland25/ResearchKit,umerkhan-apple/ResearchKit,weijentu/ResearchKit,KaiCode2/ResearchKit