switch xfermodes over to sk_sp

samplecode/SampleXfermodesBlur.cpp

Index: samplecode/SampleXfermodesBlur.cpp
diff --git a/samplecode/SampleXfermodesBlur.cpp b/samplecode/SampleXfermodesBlur.cpp
index 52419a06d0adb4d3669bc64dd14460aaa4dcd127..cab13391ed0468d6ef1a40eb37e48a5e378ce362 100644
--- a/samplecode/SampleXfermodesBlur.cpp
+++ b/samplecode/SampleXfermodesBlur.cpp
@@ -39,7 +39,7 @@ class XfermodesBlurView : public SampleView {
     SkBitmap    fBG;
     SkBitmap    fSrcB, fDstB;
 
-    void draw_mode(SkCanvas* canvas, SkXfermode* mode, int alpha,
+    void draw_mode(SkCanvas* canvas, sk_sp<SkXfermode> mode, int alpha,
                    SkScalar x, SkScalar y) {
         SkPaint p;
         SkMaskFilter* mf = SkBlurMaskFilter::Create(kNormal_SkBlurStyle,
@@ -58,7 +58,7 @@ class XfermodesBlurView : public SampleView {
         r.offset(x, y);
         canvas->drawOval(r, p);
 
-        p.setXfermode(mode);
+        p.setXfermode(std::move(mode));
 
         // draw a square overlapping the circle
         // in the lower right of the canvas
@@ -163,8 +163,6 @@ protected:
         for (int twice = 0; twice < 2; twice++) {
             SkScalar x = x0, y = 0;
             for (size_t i = 0; i < SK_ARRAY_COUNT(gModes); i++) {
-                SkXfermode* mode = SkXfermode::Create(gModes[i].fMode);
-                SkAutoUnref aur(mode);
                 SkRect r;
                 r.set(x, y, x+w, y+h);
 
@@ -174,7 +172,8 @@ protected:
                 canvas->drawRect(r, p);
 
                 canvas->saveLayer(&r, nullptr);
-                draw_mode(canvas, mode, twice ? 0x88 : 0xFF, r.fLeft, r.fTop);
+                draw_mode(canvas, SkXfermode::Make(gModes[i].fMode),
+                          twice ? 0x88 : 0xFF, r.fLeft, r.fTop);
                 canvas->restore();
 
                 r.inset(-SK_ScalarHalf, -SK_ScalarHalf);