How can I build the rendering plugin example on OS X 10.10?

I'm just beginning to get into native plugin rendering in Unity, and I downloaded the rendering plugin example from the documentation. The built plugin that's already in the project displays properly, but when I try to re-build the plugin by opening the project in Xcode, I get several undeclared identifier errors, including but not limited to:

 Use of undeclared identifier 'GL_CULL_FACE'
 
 Use of undeclared identifier 'GL_LIGHTING'
 
 Use of undeclared identifier 'GL_BLEND'
 
 Use of undeclared identifier 'GL_ALPHATEST'

I'm sure it's something simple like linking a different version of OpenGL, but I'm unsure how to proceed since I haven't had a lot of experience with OS X/OpenGL. I'm using Mac OS X 10.10 (Yosemite) and Unity 4.5.4f1.