Add some backend flexibility for shader declarations in ProgramBuilding.

src/gpu/glsl/GrGLSLVarying.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 "glsl/GrGLSLVarying.h"
 
 #include "glsl/GrGLSLProgramBuilder.h"
@@ skipping 87 matching lines @@
     for (int j = 0; j < fVertexInputs.count(); ++j) {
         const GrGLSLShaderVar& attr = fVertexInputs[j];
         // if attribute already added, don't add it again
         if (attr.getName().equals(var.getName())) {
             return;
         }
     }
     fVertexInputs.push_back(var);
 }
 
+void GrGLSLVaryingHandler::finalize() {
+    this->onFinalize();
+}
+
 void GrGLSLVaryingHandler::appendDecls(const VarArray& vars, SkString* out) const {
     for (int i = 0; i < vars.count(); ++i) {
         vars[i].appendDecl(fProgramBuilder->glslCaps(), out);
         out->append(";");
     }
 }
 
 void GrGLSLVaryingHandler::getVertexDecls(SkString* inputDecls, SkString* outputDecls) const {
     this->appendDecls(fVertexInputs, inputDecls);
     this->appendDecls(fVertexOutputs, outputDecls);
 }
 
 void GrGLSLVaryingHandler::getGeomDecls(SkString* inputDecls, SkString* outputDecls) const {
     this->appendDecls(fGeomInputs, inputDecls);
     this->appendDecls(fGeomOutputs, outputDecls);
 }
 
 void GrGLSLVaryingHandler::getFragDecls(SkString* inputDecls, SkString* outputDecls) const {
     // We should not have any outputs in the fragment shader when using version 1.10
     SkASSERT(k110_GrGLSLGeneration != fProgramBuilder->glslCaps()->generation() ||
              fFragOutputs.empty());
     this->appendDecls(fFragInputs, inputDecls);
     this->appendDecls(fFragOutputs, outputDecls);
 }