Autoresizing issue of UICollectionViewCell contentView’s frame in Storyboard prototype cell (Xcode 6, iOS 8 SDK) happens when running on iOS 7 only

contentView is broken. It can be also fixed in awakeFromNib

ObjC:

- (void)awakeFromNib {

    [super awakeFromNib];

    self.contentView.frame = self.bounds;
    self.contentView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
}

Swift3:

override func awakeFromNib() {
    super.awakeFromNib()

    self.contentView.frame = self.bounds
    self.contentView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
}