reland "extract some common code from PictureRenderer"

re-lands https://codereview.chromium.org/273703006/

NOTRY=True
R=bungeman@google.com, djsollen@google.com

Author: epoger@google.com

Review URL: https://codereview.chromium.org/278633002

git-svn-id: http://skia.googlecode.com/svn/trunk@14662 2bbb7eff-a529-9590-31e7-b0007b416f81
8 files changed