switch xfermodes over to sk_sp

src/core/SkCanvas.cpp

 /*
  * Copyright 2008 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBitmapDevice.h"
 #include "SkCanvas.h"
 #include "SkCanvasPriv.h"
@@ skipping 463 matching lines @@
              *      Remove the imagefilter and the xfermode from the paint that we (AutoDrawLooper)
              *      return (fPaint). We then draw the primitive (using srcover) into a cleared
              *      buffer/surface.
              *  3. Restore the layer created in #1
              *      The imagefilter is passed the buffer/surface from the layer (now filled with the
              *      src pixels of the primitive). It returns a new "filtered" buffer, which we
              *      draw onto the previous layer using the xfermode from the original paint.
              */
             SkPaint tmp;
             tmp.setImageFilter(fPaint->getImageFilter());
-            tmp.setXfermode(fPaint->getXfermode());
+            tmp.setXfermode(sk_ref_sp(fPaint->getXfermode()));
             SkRect storage;
             if (rawBounds) {
                 // Make rawBounds include all paint outsets except for those due to image filters.
                 rawBounds = &apply_paint_to_bounds_sans_imagefilter(*fPaint, *rawBounds, &storage);
             }
             (void)canvas->internalSaveLayer(SkCanvas::SaveLayerRec(rawBounds, &tmp),
                                             SkCanvas::kFullLayer_SaveLayerStrategy);
             fTempLayerForImageFilter = true;
             // we remove the imagefilter/xfermode inside doNext()
         }
@@ skipping 2546 matching lines @@
 
 SkAutoCanvasMatrixPaint::~SkAutoCanvasMatrixPaint() {
     fCanvas->restoreToCount(fSaveCount);
 }
 
 #ifdef SK_SUPPORT_LEGACY_NEW_SURFACE_API
 SkSurface* SkCanvas::newSurface(const SkImageInfo& info, const SkSurfaceProps* props) {
     return this->makeSurface(info, props).release();
 }
 #endif