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

src/pipe/SkPipeCanvas.cpp

Index: src/pipe/SkPipeCanvas.cpp
diff --git a/src/pipe/SkPipeCanvas.cpp b/src/pipe/SkPipeCanvas.cpp
index 224451f2cac2f21f4d19dfbbd07e5386841f46f5..21b7267d74b72f47a9a719e64f3c33f3a0872311 100644
--- a/src/pipe/SkPipeCanvas.cpp
+++ b/src/pipe/SkPipeCanvas.cpp
@@ -318,21 +318,21 @@ void SkPipeCanvas::didSetMatrix(const SkMatrix& matrix) {
     this->INHERITED::didSetMatrix(matrix);
 }
 
-void SkPipeCanvas::onClipRect(const SkRect& rect, SkRegion::Op op, ClipEdgeStyle edgeStyle) {
+void SkPipeCanvas::onClipRect(const SkRect& rect, ClipOp op, ClipEdgeStyle edgeStyle) {
     fStream->write32(pack_verb(SkPipeVerb::kClipRect, ((unsigned)op << 1) | edgeStyle));
     fStream->write(&rect, 4 * sizeof(SkScalar));
 
     this->INHERITED::onClipRect(rect, op, edgeStyle);
 }
 
-void SkPipeCanvas::onClipRRect(const SkRRect& rrect, SkRegion::Op op, ClipEdgeStyle edgeStyle) {
+void SkPipeCanvas::onClipRRect(const SkRRect& rrect, ClipOp op, ClipEdgeStyle edgeStyle) {
     fStream->write32(pack_verb(SkPipeVerb::kClipRRect, ((unsigned)op << 1) | edgeStyle));
     write_rrect(fStream, rrect);
 
     this->INHERITED::onClipRRect(rrect, op, edgeStyle);
 }
 
-void SkPipeCanvas::onClipPath(const SkPath& path, SkRegion::Op op, ClipEdgeStyle edgeStyle) {
+void SkPipeCanvas::onClipPath(const SkPath& path, ClipOp op, ClipEdgeStyle edgeStyle) {
     SkPipeWriter writer(this);
     writer.write32(pack_verb(SkPipeVerb::kClipPath, ((unsigned)op << 1) | edgeStyle));
     writer.writePath(path);
@@ -340,7 +340,7 @@ void SkPipeCanvas::onClipPath(const SkPath& path, SkRegion::Op op, ClipEdgeStyle
     this->INHERITED::onClipPath(path, op, edgeStyle);
 }
 
-void SkPipeCanvas::onClipRegion(const SkRegion& deviceRgn, SkRegion::Op op) {
+void SkPipeCanvas::onClipRegion(const SkRegion& deviceRgn, ClipOp op) {
     SkPipeWriter writer(this);
     writer.write32(pack_verb(SkPipeVerb::kClipRegion, (unsigned)op << 1));
     writer.writeRegion(deviceRgn);