SkPDF: ASAN fix: don't double ref new SkPDFBitmap objects

src/pdf/SkPDFDevice.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 "SkPDFDevice.h"
 
 #include "SkAnnotation.h"
@@ skipping 2264 matching lines @@
         // TODO(http://skbug.com/4378): implement colorfilter on other
         // draw calls.  This code here works for all
         // drawBitmap*()/drawImage*() calls amd ImageFilters (which
         // rasterize a layer on this backend).  Fortuanely, this seems
         // to be how Chromium impements most color-filters.
         autoImageUnref.reset(color_filter(image, colorFilter));
         image = autoImageUnref;
         // TODO(halcanary): de-dupe this by caching filtered images.
         // (maybe in the resource cache?)
     }
-    SkAutoTUnref<SkPDFObject> pdfimage(fCanon->findPDFBitmap(image));
+    SkAutoTUnref<SkPDFObject> pdfimage(SkSafeRef(fCanon->findPDFBitmap(image)));
     if (!pdfimage) {
         pdfimage.reset(SkPDFCreateBitmapObject(image));
         if (!pdfimage) {
             return;
         }
         fCanon->addPDFBitmap(image->uniqueID(), pdfimage);
     }
-    SkPDFUtils::DrawFormXObject(this->addXObjectResource(SkRef(pdfimage.get())),
+    SkPDFUtils::DrawFormXObject(this->addXObjectResource(pdfimage.get()),
                                 &content.entry()->fContent);
 }