Code review comment for lp:~kdub/mir/split-mesa

Oh, actually, further to Alberto's comments, that does need fixing:

+ EGLNativeDisplayType egl_native_display() const override;

because the definition of EGLNativeDisplayType can change profoundly depending on where it is included and what the assumed EGL platform is (decided a pre-processing time). Hence it fails the one-definition-rule and will occasionally cause build failures.

A good compromise I think is to write code that assumes EGLNativeDisplayType is always going to be compatible with a pointer. So please change EGLNativeDisplayType to use MirEGLNativeDisplayType (which is currently defined in mir_toolkit/client_types.h). Although it's better if we never need to return it from a function at all...