SkNonCopyable should be used with private inheritance.

src/core/SkMatrixClipStateMgr.h

Index: src/core/SkMatrixClipStateMgr.h
diff --git a/src/core/SkMatrixClipStateMgr.h b/src/core/SkMatrixClipStateMgr.h
index b2275831387beca1000544768ca5f71f18760488..270eacd0328293e4d2fbcf207468235dd8a995af 100644
--- a/src/core/SkMatrixClipStateMgr.h
+++ b/src/core/SkMatrixClipStateMgr.h
@@ -53,7 +53,7 @@ public:
     static const int32_t kIdentityWideOpenStateID = 0;
     static const int kIdentityMatID = 0;
 
-    class MatrixClipState : public SkNoncopyable {
+    class MatrixClipState : SkNoncopyable {
     public:
         class MatrixInfo {
         public:
@@ -108,7 +108,7 @@ public:
             typedef SkNoncopyable INHERITED;
         };
 
-        class ClipInfo : public SkNoncopyable {
+        class ClipInfo : SkNoncopyable {
         public:
             ClipInfo() {}