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

src/gpu/GrDefaultGeoProcFactory.cpp

Index: src/gpu/GrDefaultGeoProcFactory.cpp
diff --git a/src/gpu/GrDefaultGeoProcFactory.cpp b/src/gpu/GrDefaultGeoProcFactory.cpp
index a798ee86ef7ead3f0df9339aee46bde23a77f342..dca6c1c017a4d8b14aa8021f4c2d7b0e20aa8e2a 100644
--- a/src/gpu/GrDefaultGeoProcFactory.cpp
+++ b/src/gpu/GrDefaultGeoProcFactory.cpp
@@ -128,12 +128,11 @@
         return gp.fFlags == this->fFlags;
     }
 
-    virtual void onGetInvariantOutputCoverage(GrInitInvariantOutput* out) const SK_OVERRIDE {
+    virtual void onComputeInvariantOutput(GrInvariantOutput* inout) const SK_OVERRIDE {
         if (fInCoverage) {
-            out->setUnknownSingleComponent();
+            inout->mulByUnknownAlpha();
         } else {
-            // uniform coverage
-            out->setKnownSingleComponent(this->coverage());
+            inout->mulByKnownAlpha(255);
         }
     }