abstract name of clipping ops, to transtion to a more restricted set

src/utils/SkDeferredCanvas.h

Index: src/utils/SkDeferredCanvas.h
diff --git a/src/utils/SkDeferredCanvas.h b/src/utils/SkDeferredCanvas.h
index faa3d66e2cb34073e194e56c6c2bfd358ae547db..05ad4cfca809c863d53cd3a96a94bb2b0b17bc58 100644
--- a/src/utils/SkDeferredCanvas.h
+++ b/src/utils/SkDeferredCanvas.h
@@ -86,10 +86,10 @@ protected:
                      int count, SkXfermode::Mode mode,
                      const SkRect* cull, const SkPaint* paint) override;
 
-    void onClipRect(const SkRect&, SkRegion::Op, ClipEdgeStyle) override;
-    void onClipRRect(const SkRRect&, SkRegion::Op, ClipEdgeStyle) override;
-    void onClipPath(const SkPath&, SkRegion::Op, ClipEdgeStyle) override;
-    void onClipRegion(const SkRegion&, SkRegion::Op) override;
+    void onClipRect(const SkRect&, ClipOp, ClipEdgeStyle) override;
+    void onClipRRect(const SkRRect&, ClipOp, ClipEdgeStyle) override;
+    void onClipPath(const SkPath&, ClipOp, ClipEdgeStyle) override;
+    void onClipRegion(const SkRegion&, ClipOp) override;
 
     void onDrawDrawable(SkDrawable*, const SkMatrix*) override;
     void onDrawPicture(const SkPicture*, const SkMatrix*, const SkPaint*) override;