Refactor the scene graph transform hierarchy to support 4x4 matrices:
* rename current Transform to TransformEffect (operates as a render tree effect)
* introduce a new Transform abstract base class, to replace current Matrix
* refactor existing Matrix as a Transform specialization
* introduce a new Matrix44 Transform specialization
* refactor the existing composition helper (ComposedMatrix) as Concat,
a Transform specialization (using composition instead of Matrix inheritance)
Change-Id: Ic3c1b499e10a0a229a7a76d4bef3dbc6a8b49194
Reviewed-on: https://skia-review.googlesource.com/c/182666
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Florin Malita <fmalita@chromium.org>
919e209d1a