Revert "Revert "Make GrAtlasTextOp a non-legacy GrMeshDrawOp""

This reverts commit e3e9628ecf863f433f26bf6107d6a39ced57fe30.

Adds blendmode_mask_* benchs to blacklist for Chromecast.
Otherwise a clean revert of the revert.

Bug: skia:
Change-Id: I9f64ae55804fa4aad97c1785834281039570c56c
Reviewed-on: https://skia-review.googlesource.com/24409
Commit-Queue: Brian Salomon <bsalomon@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
diff --git a/src/gpu/GrProcessorSet.h b/src/gpu/GrProcessorSet.h
index 666e1c3..e3fe4c6 100644
--- a/src/gpu/GrProcessorSet.h
+++ b/src/gpu/GrProcessorSet.h
@@ -134,6 +134,7 @@
 
     bool isFinalized() const { return SkToBool(kFinalized_Flag & fFlags); }
 
+    /** These are valid only for non-LCD coverage. */
     static const GrProcessorSet& EmptySet();
     static constexpr const Analysis EmptySetAnalysis() { return Analysis(Empty::kEmpty); }