ccpr: Add an MSAA atlas mode

Adds the option to use a multisampled (or mixed sampled) atlas, and
uses the sample mask and stencil buffer instead of coverage counts.

Bug: skia:
Change-Id: I9fb76d17895ae25208124f6c27e37977ac31b5eb
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/227428
Commit-Queue: Chris Dalton <csmartdalton@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
diff --git a/src/gpu/ccpr/GrCCPathCache.cpp b/src/gpu/ccpr/GrCCPathCache.cpp
index 08eda25..30400cb 100644
--- a/src/gpu/ccpr/GrCCPathCache.cpp
+++ b/src/gpu/ccpr/GrCCPathCache.cpp
@@ -380,7 +380,7 @@
     SkASSERT(!this->hasBeenEvicted());
     SkASSERT(fOnFlushRefCnt > 0);
     SkASSERT(fCachedAtlas);
-    SkASSERT(GrCCAtlas::CoverageType::kFP16_CoverageCount == fCachedAtlas->coverageType());
+    SkASSERT(GrCCAtlas::CoverageType::kA8_LiteralCoverage != fCachedAtlas->coverageType());
 
     ReleaseAtlasResult releaseAtlasResult = this->releaseCachedAtlas(pathCache);