remove SkDataSet, and just store a key/value in SkAnnotation

BUG=
R=mtklein@google.com

Review URL: https://codereview.chromium.org/27208002

git-svn-id: http://skia.googlecode.com/svn/trunk@11759 2bbb7eff-a529-9590-31e7-b0007b416f81
7 files changed