Add appendPrecisionModifier method to GrGLSLShaderBuilder

src/gpu/effects/GrTextureDomain.cpp

Index: src/gpu/effects/GrTextureDomain.cpp
diff --git a/src/gpu/effects/GrTextureDomain.cpp b/src/gpu/effects/GrTextureDomain.cpp
index d3850a31c24041021c02f8770dc926bad2ecb6d9..724b3ec21d28a4c04125aee2412b37216665e1f6 100644
--- a/src/gpu/effects/GrTextureDomain.cpp
+++ b/src/gpu/effects/GrTextureDomain.cpp
@@ -103,11 +103,9 @@ void GrTextureDomain::GLDomain::sampleTexture(GrGLSLShaderBuilder* builder,
                                                           inCoords.c_str());
                 builder->codeAppend(";");
 
-                builder->codeAppend(GrGLSLShaderVar::PrecisionString(glslCaps,
-                                                                     kHigh_GrSLPrecision));
+                builder->appendPrecisionModifier(kHigh_GrSLPrecision);
                 builder->codeAppendf("float x = (%s).x;", inCoords.c_str());
-                builder->codeAppend(GrGLSLShaderVar::PrecisionString(glslCaps,
-                                                                     kHigh_GrSLPrecision));
+                builder->appendPrecisionModifier(kHigh_GrSLPrecision);
                 builder->codeAppendf("float y = (%s).y;", inCoords.c_str());
 
                 builder->codeAppendf("x = abs(2.0*(x - %s.x)/(%s.z - %s.x) - 1.0);",