Revert[8] "replace SkXfermode obj with SkBlendMode enum in paints"

src/xps/SkXPSDevice.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkTypes.h"
 #if defined(SK_BUILD_FOR_WIN32)
 
@@ skipping 1202 matching lines @@
     path.addRRect(rr);
     this->drawPath(d, path, paint, nullptr, true);
 }
 
 void SkXPSDevice::internalDrawRect(const SkDraw& d,
                                    const SkRect& r,
                                    bool transformRect,
                                    const SkPaint& paint) {
     //Exit early if there is nothing to draw.
     if (d.fRC->isEmpty() ||
-        (paint.getAlpha() == 0 && paint.getXfermode() == nullptr)) {
+        (paint.getAlpha() == 0 && paint.isSrcOver())) {
         return;
     }
 
     //Path the rect if we can't optimize it.
     if (rect_must_be_pathed(paint, *d.fMatrix)) {
         SkPath tmp;
         tmp.addRect(r);
         tmp.setFillType(SkPath::kWinding_FillType);
         this->drawPath(d, tmp, paint, nullptr, true);
         return;
@@ skipping 295 matching lines @@
 
 void SkXPSDevice::drawPath(const SkDraw& d,
                            const SkPath& platonicPath,
                            const SkPaint& origPaint,
                            const SkMatrix* prePathMatrix,
                            bool pathIsMutable) {
     SkTCopyOnFirstWrite<SkPaint> paint(origPaint);
 
     // nothing to draw
     if (d.fRC->isEmpty() ||
-        (paint->getAlpha() == 0 && paint->getXfermode() == nullptr)) {
+        (paint->getAlpha() == 0 && paint->isSrcOver())) {
         return;
     }
 
     SkPath modifiedPath;
     const bool paintHasPathEffect = paint->getPathEffect()
                                  || paint->getStyle() != SkPaint::kFill_Style;
 
     //Apply pre-path matrix [Platonic-path -> Skeletal-path].
     SkMatrix matrix = *d.fMatrix;
     SkPath* skeletalPath = const_cast<SkPath*>(&platonicPath);
@@ skipping 729 matching lines @@
         //SkXPSDevice* dev = new SkXPSDevice(this);
         //SkSize s = SkSize::Make(width, height);
         //dev->BeginCanvas(s, s, SkMatrix::I());
         //return dev;
     }
 #endif
     return new SkXPSDevice(this->fXpsFactory.get());
 }
 
 #endif//defined(SK_BUILD_FOR_WIN32)