GrFP can express distance vector field req., program builder declares variable for it

src/gpu/vk/GrVkProgramDesc.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #include "GrVkProgramDesc.h"
 
 //#include "GrVkProcessor.h"
 #include "GrProcessor.h"
@@ skipping 142 matching lines @@
     }
 
     header->fOutputSwizzle = glslCaps.configOutputSwizzle(rt->config()).asKey();
 
     if (pipeline.ignoresCoverage()) {
         header->fIgnoresCoverage = 1;
     } else {
         header->fIgnoresCoverage = 0;
     }
 
+    if (pipeline.usesDistanceVectorField()) {
+        header->fUsesDistanceVectorField = 1;
+    } else {
+        header->fUsesDistanceVectorField = 0;
+    }
+
     header->fSnapVerticesToPixelCenters = pipeline.snapVerticesToPixelCenters();
     header->fColorEffectCnt = pipeline.numColorFragmentProcessors();
     header->fCoverageEffectCnt = pipeline.numCoverageFragmentProcessors();
     vkDesc->finalize();
     return true;
 }