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

include/utils/SkLuaCanvas.h

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkLuaCanvas_DEFINED
 #define SkLuaCanvas_DEFINED
 
@@ skipping 45 matching lines @@
     void onDrawImageRect(const SkImage*, const SkRect* src, const SkRect& dst,
                          const SkPaint*, SrcRectConstraint) override;
     void onDrawBitmapNine(const SkBitmap&, const SkIRect& center, const SkRect& dst,
                           const SkPaint*) override;
     void onDrawVertices(VertexMode vmode, int vertexCount,
                         const SkPoint vertices[], const SkPoint texs[],
                         const SkColor colors[], SkXfermode* xmode,
                         const uint16_t indices[], int indexCount,
                         const SkPaint&) 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 onDrawPicture(const SkPicture*, const SkMatrix*, const SkPaint*) override;
 
 private:
     lua_State*  fL;
     SkString    fFunc;
 
     void sendverb(const char verb[]);
 
     typedef SkCanvas INHERITED;
 };
 
 #endif