Revert of Implement Porter Duff XP with a blend table

include/gpu/GrXferProcessor.h

Index: include/gpu/GrXferProcessor.h
diff --git a/include/gpu/GrXferProcessor.h b/include/gpu/GrXferProcessor.h
index 85e5aa04ed935e9d99e819be55ae8a805d521105..8458a620feb07805de18c474d7c679408cbad972 100644
--- a/include/gpu/GrXferProcessor.h
+++ b/include/gpu/GrXferProcessor.h
@@ -50,6 +50,10 @@
 };
 
 static const int kGrBlendEquationCnt = kLast_GrBlendEquation + 1;
+
+inline bool GrBlendEquationIsAdvanced(GrBlendEquation equation) {
+    return equation >= kFirstAdvancedGrBlendEquation;
+}
 
 /**
  * Coeffecients for alpha-blending.
@@ -139,6 +143,10 @@
          */
         kOverrideColor_OptFlag            = 0x8,
         /**
+         * Set CoverageDrawing_StateBit
+         */
+        kSetCoverageDrawing_OptFlag       = 0x10,
+        /**
          * Can tweak alpha for coverage. Currently this flag should only be used by a batch
          */
         kCanTweakAlphaForCoverage_OptFlag = 0x20,