Factory methods for heap-allocated SkAnnotation objects.

This is part of an effort to ensure that all SkPaint effects can only be
allocated on the heap.

This patch makes the constructors of SkAnnotation non-public and instead
provides factory methods for creating these objects on the heap.

BUG=skia:2187
R=reed@google.com, mtklein@google.com, scroggo@google.com

Author: dominikg@chromium.org

Review URL: https://codereview.chromium.org/181703003

git-svn-id: http://skia.googlecode.com/svn/trunk@13605 2bbb7eff-a529-9590-31e7-b0007b416f81
4 files changed