Allow users to build on top of, instead of beneath, SkRefCnt.

Alternative to r11811.

The Chromium half of this can be seen at https://codereview.chromium.org/40973002/ .

R=reed@google.com

Review URL: https://codereview.chromium.org/40503002

git-svn-id: http://skia.googlecode.com/svn/trunk@11967 2bbb7eff-a529-9590-31e7-b0007b416f81
2 files changed