[skottie] Preserve image aspect ratio

When the intrinsic image dimensions don't match the declared asset size,
use an aspect-preserving matrix for scaling.

Bug: skia:
TBR=
Change-Id: Ie361f464fdbc2c32cb898c9f97103521162b46a7
Reviewed-on: https://skia-review.googlesource.com/c/168274
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Florin Malita <fmalita@chromium.org>
Auto-Submit: Florin Malita <fmalita@chromium.org>
1 file changed