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

src/gpu/glsl/GrGLSLFragmentProcessor.h

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrGLSLFragmentProcessor_DEFINED
 #define GrGLSLFragmentProcessor_DEFINED
 
@@ skipping 43 matching lines @@
 
     struct EmitArgs {
         EmitArgs(GrGLSLFPFragmentBuilder* fragBuilder,
                  GrGLSLUniformHandler* uniformHandler,
                  const GrGLSLCaps* caps,
                  const GrFragmentProcessor& fp,
                  const char* outputColor,
                  const char* inputColor,
                  const GrGLSLTransformedCoordsArray& coords,
                  const SamplerHandle* texSamplers,
-                 const SamplerHandle* bufferSamplers)
+                 const SamplerHandle* bufferSamplers,
+                 bool gpImplementsDistanceVector)
             : fFragBuilder(fragBuilder)
             , fUniformHandler(uniformHandler)
             , fGLSLCaps(caps)
             , fFp(fp)
             , fOutputColor(outputColor)
             , fInputColor(inputColor)
             , fCoords(coords)
             , fTexSamplers(texSamplers)
-            , fBufferSamplers(bufferSamplers) {}
+            , fBufferSamplers(bufferSamplers)
+            , fGpImplementsDistanceVector(gpImplementsDistanceVector){}
         GrGLSLFPFragmentBuilder* fFragBuilder;
         GrGLSLUniformHandler* fUniformHandler;
         const GrGLSLCaps* fGLSLCaps;
         const GrFragmentProcessor& fFp;
         const char* fOutputColor;
         const char* fInputColor;
         const GrGLSLTransformedCoordsArray& fCoords;
         const SamplerHandle* fTexSamplers;
         const SamplerHandle* fBufferSamplers;
+        bool fGpImplementsDistanceVector;
     };
 
     virtual void emitCode(EmitArgs&) = 0;
 
     void setData(const GrGLSLProgramDataManager& pdman, const GrFragmentProcessor& processor);
 
     static void GenKey(const GrProcessor&, const GrGLSLCaps&, GrProcessorKeyBuilder*) {}
 
     int numChildProcessors() const { return fChildProcessors.count(); }
 
@@ skipping 26 matching lines @@
 
 private:
     void internalEmitChild(int, const char*, const char*, EmitArgs&);
 
     SkTArray<GrGLSLFragmentProcessor*, true> fChildProcessors;
 
     friend class GrFragmentProcessor;
 };
 
 #endif