Add GrShaderFlags enum

src/gpu/gl/GrGLUniformHandler.h

Index: src/gpu/gl/GrGLUniformHandler.h
diff --git a/src/gpu/gl/GrGLUniformHandler.h b/src/gpu/gl/GrGLUniformHandler.h
index a782bcb1c3d7494aa11a317d5da6913bdea7fc3f..7ce826cc5de6c34b310323439d0913ae4407b074 100644
--- a/src/gpu/gl/GrGLUniformHandler.h
+++ b/src/gpu/gl/GrGLUniformHandler.h
@@ -38,7 +38,7 @@ private:
                                           int arrayCount,
                                           const char** outName) override;
 
-    void appendUniformDecls(ShaderVisibility, SkString*) const override;
+    void appendUniformDecls(GrShaderFlags visibility, SkString*) const override;
 
     // Manually set uniform locations for all our uniforms.
     void bindUniformLocations(GrGLuint programID, const GrGLCaps& caps);