Create GrGLSLVaryingHandler class for program building

src/gpu/glsl/GrGLSLShaderBuilder.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 "glsl/GrGLSLShaderBuilder.h"
 #include "glsl/GrGLSLCaps.h"
 #include "glsl/GrGLSLShaderVar.h"
@@ skipping 172 matching lines @@
 }
 
 void GrGLSLShaderBuilder::finalize(uint32_t visibility) {
     SkASSERT(!fFinalized);
     this->versionDecl() = fProgramBuilder->glslCaps()->versionDeclString();
     this->compileAndAppendLayoutQualifiers();
     SkASSERT(visibility);
     fProgramBuilder->appendUniformDecls((GrGLSLProgramBuilder::ShaderVisibility) visibility,
                                         &this->uniforms());
     this->appendDecls(fInputs, &this->inputs());
-    // We should not have any outputs in the fragment shader when using version 1.10
-    SkASSERT(GrGLSLProgramBuilder::kFragment_Visibility != visibility ||
-             k110_GrGLSLGeneration != fProgramBuilder->glslCaps()->generation() ||
-             fOutputs.empty());
     this->appendDecls(fOutputs, &this->outputs());
     this->onFinalize();
     // append the 'footer' to code
     this->code().append("}");
 
     for (int i = 0; i <= fCodeIndex; i++) {
         fCompilerStrings[i] = fShaderStrings[i].c_str();
         fCompilerStringLengths[i] = (int)fShaderStrings[i].size();
     }
 
     fFinalized = true;
 }