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

ui/gfx/skbitmap_operations.cc

Index: ui/gfx/skbitmap_operations.cc
diff --git a/ui/gfx/skbitmap_operations.cc b/ui/gfx/skbitmap_operations.cc
index 7e2750604bcccb4e82cef9364ae1f6ef90e6eec0..3d113292adcebf0e46a2f4fa4f0ef2ad03c004e3 100644
--- a/ui/gfx/skbitmap_operations.cc
+++ b/ui/gfx/skbitmap_operations.cc
@@ -8,6 +8,7 @@
 #include <string.h>
 
 #include "base/logging.h"
+#include "skia/ext/refptr.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "third_party/skia/include/core/SkColorFilter.h"
@@ -759,10 +760,10 @@ SkBitmap SkBitmapOperations::CreateColorMask(const SkBitmap& bitmap,
 
   SkCanvas canvas(color_mask);
 
-  SkColorFilter* color_filter = SkColorFilter::CreateModeFilter(
+  skia::RefPtr<SkColorFilter> color_filter = SkColorFilter::CreateModeFilter(
       c, SkXfermode::kSrcIn_Mode);
   SkPaint paint;
-  paint.setColorFilter(color_filter)->unref();
+  paint.setColorFilter(color_filter.get());
   canvas.drawBitmap(bitmap, SkIntToScalar(0), SkIntToScalar(0), &paint);
   return color_mask;
 }
@@ -795,9 +796,10 @@ SkBitmap SkBitmapOperations::CreateDropShadow(
     SkBitmap shadow_image = SkBitmapOperations::CreateColorMask(bitmap,
                                                                 shadow.color());
 
-    paint.setImageFilter(
+    skia::RefPtr<SkBlurImageFilter> filter =
         new SkBlurImageFilter(SkDoubleToScalar(shadow.blur()),
-                              SkDoubleToScalar(shadow.blur())))->unref();
+                              SkDoubleToScalar(shadow.blur()));
+    paint.setImageFilter(filter.get());
 
     canvas.saveLayer(0, &paint);
     canvas.drawBitmap(shadow_image,