Create GrGLSLVaryingHandler class for program building

src/gpu/glsl/GrGLSLShaderBuilder.h

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrGLSLShaderBuilder_DEFINED
 #define GrGLSLShaderBuilder_DEFINED
 
 #include "GrAllocator.h"
 #include "glsl/GrGLSLShaderVar.h"
 #include "SkTDArray.h"
 
 #include <stdarg.h>
 
 class GrGLSLProgramBuilder;
 class GrGLSLTextureSampler;
 
 /**
   base class for all shaders builders
 */
 class GrGLSLShaderBuilder {
 public:
     GrGLSLShaderBuilder(GrGLSLProgramBuilder* program);
     virtual ~GrGLSLShaderBuilder() {}
 
-    void addInput(const GrGLSLShaderVar& input) { fInputs.push_back(input); }
-    void addOutput(const GrGLSLShaderVar& output) { fOutputs.push_back(output); }
-
     /*
      * We put texture lookups in the base class because it is TECHNICALLY possible to do texture
      * lookups in any kind of shader.  However, for the time being using these calls on non-fragment
      * shaders will result in a shader compilation error as texture sampler uniforms are only
      * visible to the fragment shader.  It would not be hard to change this behavior, if someone
      * actually wants to do texture lookups in a non-fragment shader
      *
      * TODO if append texture lookup is used on a non-fragment shader, sampler uniforms should be
      * made visible to that shaders
      */
@@ skipping 150 matching lines @@
     VarArray fOutputs;
     uint32_t fFeaturesAddedMask;
     SkSTArray<1, SkString> fLayoutParams[kLastInterfaceQualifier + 1];
     int fCodeIndex;
     bool fFinalized;
 
     friend class GrGLProgramBuilder;
     friend class GrGLPathProgramBuilder; // to access fInputs.
 };
 #endif