We should replace GeometryPool entirely

[andybak]

From the comments in GeometryPool.cs :

/// GeometryPool stores mesh data in convenient and C#-accessible data structures.
///
/// Quite often, GeometryPool data is associated with a particular UnityEngine.Mesh to which
/// data changes are pushed with CopyToMesh(mesh). This trades off increased memory usage for
/// efficient updates, and is analagous to a CPU cache. 

Unity has a much more efficient mesh API now so we could get rid of all this baggage.

First step might be to delete these fields:

    public List<Vector3> m_Vertices;
    public List<int> m_Tris;
    public List<Vector3> m_Normals;
    public TexcoordData m_Texcoord0;
    public TexcoordData m_Texcoord1;
    public TexcoordData m_Texcoord2;

and then see what breaks...