use Make instead of Create to return a shared shader

src/core/SkPictureShader.h

Index: src/core/SkPictureShader.h
diff --git a/src/core/SkPictureShader.h b/src/core/SkPictureShader.h
index 8cccd251d558db6d80d383e5c88bb1e3d1e4fdae..dbda8b2ed2492158b616d83efb96e8d05e05dc61 100644
--- a/src/core/SkPictureShader.h
+++ b/src/core/SkPictureShader.h
@@ -22,8 +22,8 @@ class SkPicture;
  */
 class SkPictureShader : public SkShader {
 public:
-    static SkShader* Create(const SkPicture*, TileMode, TileMode, const SkMatrix*,
-                                   const SkRect*);
+    static sk_sp<SkShader> Make(const SkPicture*, TileMode, TileMode, const SkMatrix*,
+                                const SkRect*);
 
     SK_TO_STRING_OVERRIDE()
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkPictureShader)
@@ -44,7 +44,8 @@ protected:
 private:
     SkPictureShader(const SkPicture*, TileMode, TileMode, const SkMatrix*, const SkRect*);
 
-    SkShader* refBitmapShader(const SkMatrix&, const SkMatrix* localMatrix, const int maxTextureSize = 0) const;
+    sk_sp<SkShader> refBitmapShader(const SkMatrix&, const SkMatrix* localMatrix,
+                                    const int maxTextureSize = 0) const;
 
     SkAutoTUnref<const SkPicture> fPicture;
     SkRect                        fTile;
@@ -53,7 +54,7 @@ private:
     class PictureShaderContext : public SkShader::Context {
     public:
         static Context* Create(void* storage, const SkPictureShader&, const ContextRec&,
-                               SkShader* bitmapShader);
+                               sk_sp<SkShader> bitmapShader);
 
         virtual ~PictureShaderContext();
 
@@ -63,11 +64,12 @@ private:
         void shadeSpan(int x, int y, SkPMColor dstC[], int count) override;
 
     private:
-        PictureShaderContext(const SkPictureShader&, const ContextRec&, SkShader* bitmapShader);
+        PictureShaderContext(const SkPictureShader&, const ContextRec&,
+                             sk_sp<SkShader> bitmapShader);
 
-        SkAutoTUnref<SkShader>  fBitmapShader;
-        SkShader::Context*      fBitmapShaderContext;
-        void*                   fBitmapShaderContextStorage;
+        sk_sp<SkShader>     fBitmapShader;
+        SkShader::Context*  fBitmapShaderContext;
+        void*               fBitmapShaderContextStorage;
 
         typedef SkShader::Context INHERITED;
     };