Offer single-param version of deepCopyTo -- much easier to migrate to colortypes

BUG=skia:
R=reed@google.com

Author: reed@chromium.org

Review URL: https://codereview.chromium.org/167683006

git-svn-id: http://skia.googlecode.com/svn/trunk@13516 2bbb7eff-a529-9590-31e7-b0007b416f81
8 files changed