Add appendPrecisionModifier method to GrGLSLShaderBuilder

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 "GrSwizzle.h"
 #include "glsl/GrGLSLShaderBuilder.h"
 #include "glsl/GrGLSLCaps.h"
@@ skipping 17 matching lines @@
 
     this->main() = "void main() {";
 }
 
 void GrGLSLShaderBuilder::declAppend(const GrGLSLShaderVar& var) {
     SkString tempDecl;
     var.appendDecl(fProgramBuilder->glslCaps(), &tempDecl);
     this->codeAppendf("%s;", tempDecl.c_str());
 }
 
+void GrGLSLShaderBuilder::appendPrecisionModifier(GrSLPrecision precision) {
+    if (fProgramBuilder->glslCaps()->usesPrecisionModifiers()) {
+        this->codeAppendf("%s ", GrGLSLPrecisionString(precision));
+    }
+}
+
 void GrGLSLShaderBuilder::emitFunction(GrSLType returnType,
                                        const char* name,
                                        int argCnt,
                                        const GrGLSLShaderVar* args,
                                        const char* body,
                                        SkString* outName) {
     this->functions().append(GrGLSLTypeString(returnType));
     fProgramBuilder->nameVariable(outName, '\0', name);
     this->functions().appendf(" %s", outName->c_str());
     this->functions().append("(");
@@ skipping 119 matching lines @@
     // 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;
 }