Add skia::RefPtr class to wrap ref counted classes from Skia.

printing/metafile_skia_wrapper.cc

Index: printing/metafile_skia_wrapper.cc
diff --git a/printing/metafile_skia_wrapper.cc b/printing/metafile_skia_wrapper.cc
index d4634ef421c42f21b8f7574d6de2a172cc796953..135d9fd3ea8dd917724733db0b91d404168d8f67 100644
--- a/printing/metafile_skia_wrapper.cc
+++ b/printing/metafile_skia_wrapper.cc
@@ -4,6 +4,7 @@
 
 #include "printing/metafile_skia_wrapper.h"
 #include "skia/ext/platform_device.h"
+#include "skia/ext/refptr.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "third_party/skia/include/core/SkDevice.h"
 #include "third_party/skia/include/core/SkMetaData.h"
@@ -20,13 +21,12 @@ const char* kCustomScaleKey = "CrCustomScale";
 // static
 void MetafileSkiaWrapper::SetMetafileOnCanvas(const SkCanvas& canvas,
                                               Metafile* metafile) {
-  MetafileSkiaWrapper* wrapper = NULL;
+  skia::RefPtr<MetafileSkiaWrapper> wrapper;
   if (metafile)
     wrapper = new MetafileSkiaWrapper(metafile);
 
   SkMetaData& meta = skia::getMetaData(canvas);
-  meta.setRefCnt(kMetafileKey, wrapper);
-  SkSafeUnref(wrapper);
+  meta.setRefCnt(kMetafileKey, wrapper.get());
 }
 
 // static