SkPDF: use sk_ref_sp

src/pdf/SkPDFGraphicState.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 "SkData.h"
 #include "SkOncePtr.h"
 #include "SkPDFCanon.h"
@@ skipping 147 matching lines @@
                                                    bool invert,
                                                    SkPDFSMaskMode sMaskMode) {
     // The practical chances of using the same mask more than once are unlikely
     // enough that it's not worth canonicalizing.
     auto sMaskDict = sk_make_sp<SkPDFDict>("Mask");
     if (sMaskMode == kAlpha_SMaskMode) {
         sMaskDict->insertName("S", "Alpha");
     } else if (sMaskMode == kLuminosity_SMaskMode) {
         sMaskDict->insertName("S", "Luminosity");
     }
-    sMaskDict->insertObjRef("G", sk_sp<SkPDFFormXObject>(SkRef(sMask)));
+    sMaskDict->insertObjRef("G", sk_ref_sp(sMask));
     if (invert) {
         sMaskDict->insertObjRef("TR", make_invert_function());
     }
 
     auto result = sk_make_sp<SkPDFDict>("ExtGState");
     result->insertObject("SMask", std::move(sMaskDict));
     return result.release();
 }
 
 static SkPDFDict* create_no_smask_graphic_state() {
@@ skipping 36 matching lines @@
     static_assert(SkPaint::kJoinCount == 3, "paint_join_mismatch");
     SkASSERT(strokeJoin >= 0 && strokeJoin <= 2);
     dict->insertInt("LJ", strokeJoin);
 
     dict->insertScalar("LW", fStrokeWidth);
     dict->insertScalar("ML", fStrokeMiter);
     dict->insertBool("SA", true);  // SA = Auto stroke adjustment.
     dict->insertName("BM", as_blend_mode(xferMode));
     dict->emitObject(stream, objNumMap, substitutes);
 }