mono/MonoGame — pull request #2933 by jamesford42 (2014-08-19 22:23:07+00:00)
Title: Matching original xna behavior.

This fixes custom processors which were working with textures and assuming that:
1. Texture2DContent.Faces[0][0] would not generate a null reference for a newly allocated and uninitialized Texture2DContent.
2. texture2DContent.Mipmaps.Add(..) would not generate a null reference for a newly allocated and uninitialized Texture2DContent.