switch surface to sk_sp

gm/multipicturedraw.cpp

Index: gm/multipicturedraw.cpp
diff --git a/gm/multipicturedraw.cpp b/gm/multipicturedraw.cpp
index a4b09b2c2fcc7bd7bd0b5b77c14d025fa98b8c9f..03934a601d5cac435fe4b3cdaabc406d641f3fc3 100644
--- a/gm/multipicturedraw.cpp
+++ b/gm/multipicturedraw.cpp
@@ -241,15 +241,14 @@ static sk_sp<SkPicture> make_sierpinski_picture() {
     return recorder.finishRecordingAsPicture();
 }
 
-static SkSurface* create_compat_surface(SkCanvas* canvas, int width, int height) {
+static sk_sp<SkSurface> create_compat_surface(SkCanvas* canvas, int width, int height) {
     SkImageInfo info = SkImageInfo::MakeN32Premul(width, height);
 
-    SkSurface* surface = canvas->newSurface(info);
+    auto surface = canvas->makeSurface(info);
     if (nullptr == surface) {
         // picture canvas returns nullptr so fall back to raster
-        surface = SkSurface::NewRaster(info);
+        surface = SkSurface::MakeRaster(info);
     }
-
     return surface;
 }
 
@@ -257,13 +256,12 @@ static SkSurface* create_compat_surface(SkCanvas* canvas, int width, int height)
 // fragments potentially generated by the MultiPictureDraw object
 class ComposeStep {
 public:
-    ComposeStep() : fSurf(nullptr), fX(0.0f), fY(0.0f), fPaint(nullptr) { }
+    ComposeStep() : fX(0.0f), fY(0.0f), fPaint(nullptr) { }
     ~ComposeStep() {
-        SkSafeUnref(fSurf);
         delete fPaint;
     }
 
-    SkSurface* fSurf;
+    sk_sp<SkSurface> fSurf;
     SkScalar   fX;
     SkScalar   fY;
     SkPaint*   fPaint;