Remove SkRefPtr

(resubmit of https://codereview.appspot.com/7030059/)
TBR=junov@google.com

Review URL: https://codereview.appspot.com/7030065

git-svn-id: http://skia.googlecode.com/svn/trunk@7030 2bbb7eff-a529-9590-31e7-b0007b416f81
18 files changed