Revert of Remove GP from drawstate, revision of invariant output for GP

src/effects/SkAlphaThresholdFilter.cpp

Index: src/effects/SkAlphaThresholdFilter.cpp
diff --git a/src/effects/SkAlphaThresholdFilter.cpp b/src/effects/SkAlphaThresholdFilter.cpp
index 317f6f09ecfaf2639e4be0290965f56a05c8781f..2703a245e058f9bfc63b2b5fa67f21aac4b5d06d 100644
--- a/src/effects/SkAlphaThresholdFilter.cpp
+++ b/src/effects/SkAlphaThresholdFilter.cpp
@@ -230,11 +230,11 @@
 
 void AlphaThresholdEffect::onComputeInvariantOutput(GrInvariantOutput* inout) const {
     if (GrPixelConfigIsAlphaOnly(this->texture(0)->config())) {
-        inout->mulByUnknownSingleComponent();
+        inout->mulByUnknownAlpha();
     } else if (GrPixelConfigIsOpaque(this->texture(0)->config()) && fOuterThreshold >= 1.f) {
-        inout->mulByUnknownOpaqueFourComponents();
+        inout->mulByUnknownOpaqueColor();
     } else {
-        inout->mulByUnknownFourComponents();
+        inout->mulByUnknownColor();
     }
 }