Add a header include to resolve a test build failure on linux.
Add a header include to resolve a test build failure on linux.

--HG--
branch : v1-9

jhu-lcsr-forks/ogre,jhu-lcsr-forks/ogre,jhu-lcsr-forks/ogre,jhu-lcsr-forks/ogre,jhu-lcsr-forks/ogre