Lift calls for setting dynamic state to Ganesh level

Previously, all backends were responsible to check for dynamic state
and update it during their internal draw calls. This CL adds
setScissor() and bindTextures() methods to GrOpsRenderTask, and places
this responsibility to update dynamic state on Ganesh instead. It also
replaces the backend-specific "onDrawMeshes" call, with a singular
"onDrawMesh" call that gets called for each mesh.

For now we keep drawMeshes() on GrOpsRenderPass for convenience, but
it will soon be removed and each call site will be responsible to set
its own dynamic state.

Change-Id: If141feae857b22cbf04416557d0c89986eda2a62
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/271976
Commit-Queue: Chris Dalton <csmartdalton@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
Reviewed-by: Jim Van Verth <jvanverth@google.com>
21 files changed