SkDrawCommand cleanup

- Remove fromJSON factories. These were unused, and many were
  incomplete or incorrect.
- Remove accessor methods (all unused) on command classes.
- Some commands used SkTLazy for optional params, others used
  manually initialized storage + pointer. (A few used strange
  sentinel values like empty rect or identity matrix). Switch
  to SkTLazy everywhere, and use the constructor that takes a
  pointer to simplify initialization in all cases.
- Use RAII for more fields (SkTDArray and sk_sp). There are a
  few of these left in the drawText commands, but that's it.

Change-Id: I34a87ad27c5efe0b94e5ae74b59a99f66a4e4cfa
Reviewed-on: https://skia-review.googlesource.com/130510
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2 files changed