Expose camera matrix in SkCanvas

3 new getters:
- localToWorld
- localToCamera
- localToDevice (same as total-matrix)

The current tracking minimizes overhead, by using a computed inverse to
produce the localToWorld/Camera. This can be change as needed in the
future (more precision, but more memory/overhead), but for now is
sufficient to try out the new APIs.

Change-Id: I85440318f36dca935124b782e110fe9c0152ae7a
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/264648
Commit-Queue: Mike Reed <reed@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
Reviewed-by: Florin Malita <fmalita@chromium.org>
7 files changed