fix up GrGLProgrambuilder precision on varyings

src/gpu/gl/builders/GrGLGeometryShaderBuilder.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrGLGeometryShaderBuilder.h"
 #include "GrGLProgramBuilder.h"
 #include "../GrGLGpu.h"
 
 GrGLGeometryBuilder::GrGLGeometryBuilder(GrGLProgramBuilder* program)
     : INHERITED(program) {
 
 }
 
-void GrGLGeometryBuilder::addVarying(const char* name, GrGLVarying* v) {
+void GrGLGeometryBuilder::addVarying(const char* name, GrSLPrecision precision, GrGLVarying* v) {
     // if we have a GS take each varying in as an array
     // and output as non-array.
     if (v->vsVarying()) {
         fInputs.push_back();
         fInputs.back().setType(v->fType);
         fInputs.back().setTypeModifier(GrGLShaderVar::kVaryingIn_TypeModifier);
+        fInputs.back().setPrecision(precision);
         fInputs.back().setUnsizedArray();
         *fInputs.back().accessName() = v->fVsOut;
         v->fGsIn = v->fVsOut;
     }
 
     if (v->fsVarying()) {
         fOutputs.push_back();
         fOutputs.back().setType(v->fType);
         fOutputs.back().setTypeModifier(GrGLShaderVar::kVaryingOut_TypeModifier);
+        fOutputs.back().setPrecision(precision);
         fProgramBuilder->nameVariable(fOutputs.back().accessName(), 'g', name);
         v->fGsOut = fOutputs.back().getName().c_str();
     }
 }
 
 bool GrGLGeometryBuilder::compileAndAttachShaders(GrGLuint programId,
         SkTDArray<GrGLuint>* shaderIds) {
     SkFAIL("Geometry shaders are not currently supported");
     return false;
 }