Remove private so shadowLayer can be copied.

components/ShadowLayer/examples/ShadowCopyController.swift

diff --git a/components/ShadowLayer/examples/ShadowCopyController.swift b/components/ShadowLayer/examples/ShadowCopyController.swift
index c1b77c2..d8def3d 100644
--- a/components/ShadowLayer/examples/ShadowCopyController.swift
+++ b/components/ShadowLayer/examples/ShadowCopyController.swift
@@ -15,7 +15,7 @@
 import UIKit
 
 class ShadowedView: UIView {
-  private var shadowLayer: MDCShadowLayer?
+  var shadowLayer: MDCShadowLayer?
 
   override init(frame: CGRect) {
     super.init(frame: frame)