Add option to add precision to varyings in shader

src/gpu/gl/builders/GrGLFragmentShaderBuilder.cpp

Index: src/gpu/gl/builders/GrGLFragmentShaderBuilder.cpp
diff --git a/src/gpu/gl/builders/GrGLFragmentShaderBuilder.cpp b/src/gpu/gl/builders/GrGLFragmentShaderBuilder.cpp
index d216a18c25821cb64b13160fc5a5e2bce83fa0b1..fef3691cd3a80f917540d378ec8bf20d7954ab11 100644
--- a/src/gpu/gl/builders/GrGLFragmentShaderBuilder.cpp
+++ b/src/gpu/gl/builders/GrGLFragmentShaderBuilder.cpp
@@ -195,8 +195,9 @@ const char* GrGLFragmentShaderBuilder::fragmentPosition() {
 
 void GrGLFragmentShaderBuilder::addVarying(GrSLType type,
                const char* name,
-               const char** fsInName) {
-    fInputs.push_back().set(type, GrGLShaderVar::kVaryingIn_TypeModifier, name);
+               const char** fsInName,
+               GrGLShaderVar::Precision fsPrecision) {
+    fInputs.push_back().set(type, GrGLShaderVar::kVaryingIn_TypeModifier, name, fsPrecision);
     if (fsInName) {
         *fsInName = name;
     }