use unique_ptr for codec factories

Will need guards for android (at least)

Bug: skia:
Change-Id: I2bb8e656997984489ef1f2e41cd3d301c4e7b947
Reviewed-on: https://skia-review.googlesource.com/26040
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Mike Reed <reed@google.com>
62 files changed