Set up texture bindings for SkMesh child effects.

We now reflect the texture and sampler information from each
of the TextureEffect fragment processor children into the
geometry processor's texture binding and sampler information.
This is somewhat fiddly as the various bindings occur in
various places in the control flow, and they all need to stay
in sync and share information.

Bug: b/40045302
Change-Id: Iefb14fa3d341746225b65eae94672a0c056171d6
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/762417
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
5 files changed