OS X: Fix a crash when switching between windowed and full screen when using the Cocoa interface.
OS X: Fix a crash when switching between windowed and full screen when using the Cocoa interface.

--HG--
branch : v1-7

ruleless/ogre,ehsan/ogre,ehsan/ogre,bhlzlx/ogre,bhlzlx/ogre,ehsan/ogre,ruleless/ogre,bhlzlx/ogre,ruleless/ogre,ehsan/ogre,ruleless/ogre,ruleless/ogre,ehsan/ogre,bhlzlx/ogre,bhlzlx/ogre,ruleless/ogre,bhlzlx/ogre