Added varying struct

src/gpu/gl/builders/GrGLVertexShaderBuilder.cpp

Index: src/gpu/gl/builders/GrGLVertexShaderBuilder.cpp
diff --git a/src/gpu/gl/builders/GrGLVertexShaderBuilder.cpp b/src/gpu/gl/builders/GrGLVertexShaderBuilder.cpp
index 76026b7a25005509701e91a874837d72555fe81f..1fa946793c64bead43fd59c8e1a83ed79d8d996d 100644
--- a/src/gpu/gl/builders/GrGLVertexShaderBuilder.cpp
+++ b/src/gpu/gl/builders/GrGLVertexShaderBuilder.cpp
@@ -23,17 +23,12 @@ GrGLVertexBuilder::GrGLVertexBuilder(GrGLProgramBuilder* program)
     , fEffectAttribOffset(0) {
 }
 
-SkString* GrGLVertexBuilder::addVarying(GrSLType type, const char* name,
-                                              const char** vsOutName) {
+void GrGLVertexBuilder::addVarying(const char* name, GrGLVarying* v) {
     fOutputs.push_back();
-    fOutputs.back().setType(type);
+    fOutputs.back().setType(v->fType);
     fOutputs.back().setTypeModifier(GrGLShaderVar::kVaryingOut_TypeModifier);
     fProgramBuilder->nameVariable(fOutputs.back().accessName(), 'v', name);
-
-    if (vsOutName) {
-        *vsOutName = fOutputs.back().getName().c_str();
-    }
-    return fOutputs.back().accessName();
+    v->fVsOut = fOutputs.back().getName().c_str();
 }
 
 void GrGLVertexBuilder::setupLocalCoords() {
@@ -63,15 +58,15 @@ void GrGLVertexBuilder::transformGLToSkiaCoords() {
 }
 
 void GrGLVertexBuilder::setupBuiltinVertexAttribute(const char* inName, GrGLSLExpr4* out) {
+    GrGLVertToFrag v(kVec4f_GrSLType);
+    fProgramBuilder->addVarying(inName, &v);
     SkString name(inName);
-    const char *vsName, *fsName;
-    fProgramBuilder->addVarying(kVec4f_GrSLType, name.c_str(), &vsName, &fsName);
     name.prepend("in");
     this->addAttribute(GrShaderVar(name.c_str(),
                                    kVec4f_GrSLType,
                                    GrShaderVar::kAttribute_TypeModifier));
-    this->codeAppendf("%s = %s;", vsName, name.c_str());
-    *out = fsName;
+    this->codeAppendf("%s = %s;", v.vsOut(), name.c_str());
+    *out = v.fsIn();
     fEffectAttribOffset++;
 }