Move textureop fallback code out of GrRTC and into AddTextureSetOps

(also renames CreateTextureSetOps to AddTextureSetOps, to match naming of
GrFillRectOp::AddFillRectOps).

Now that GrTextureOp can add more than one op to the GrRTC, it can take
over ownership of its fallback code for the texture set. It already had
taken over the code for non src-over blends when drawing a single texture.

Besides consolidating where the logic of converting TextureSetEntries into
op data lives, this makes the fallback case more consistent in terms of
performance. Previously, it would go through GrRTC::drawTexturedQuad,
which attempts to merge the clip with the draw for correctness reasons.
A batch never attempted these optimizations, so now even when one op per
quad is required, there won't be the overhead of comparing clips.

Change-Id: I30883e3bd45ed4386f81584e3d68229c46b17e47
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/255781
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Michael Ludwig <michaelludwig@google.com>
4 files changed