Remove support for multiple coverage processors from GrPaint API.

Change-Id: I82276e38ea4a5524127176eb5a34066b6cb06d88
Bug: skia:10217
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/304799
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: John Stiles <johnstiles@google.com>
diff --git a/src/gpu/GrRenderTargetContext.cpp b/src/gpu/GrRenderTargetContext.cpp
index 5213946..bc84e7d 100644
--- a/src/gpu/GrRenderTargetContext.cpp
+++ b/src/gpu/GrRenderTargetContext.cpp
@@ -776,8 +776,7 @@
 
     SkPMColor4f* constColor = nullptr;
     SkPMColor4f paintColor;
-    if (!ss && !paint.numCoverageFragmentProcessors() &&
-        paint.isConstantBlendedColor(&paintColor)) {
+    if (!ss && !paint.hasCoverageFragmentProcessor() && paint.isConstantBlendedColor(&paintColor)) {
         // Only consider clears/rrects when it's easy to guarantee 100% fill with single color
         constColor = &paintColor;
     }
@@ -1444,7 +1443,7 @@
         return false;
     }
 
-    paint.addCoverageFragmentProcessor(std::move(fp));
+    paint.setCoverageFragmentProcessor(std::move(fp));
 
     SkRect bounds = outer->getBounds();
     if (GrAAType::kCoverage == aaType) {