Mark SkDrawPictureCallback with SK_API, so that it can be derived from by SK_API classes

R=reed@google.com

Author: vmpstr@chromium.org

Review URL: https://chromiumcodereview.appspot.com/15745015

git-svn-id: http://skia.googlecode.com/svn/trunk/include@9249 2bbb7eff-a529-9590-31e7-b0007b416f81
1 file changed