Unreviewed build fix for the GTK port after r142595.
Adding the TextureMapperFPSCounter files to the list of build targets
in case of using the OpenGL texture mapper.

* GNUmakefile.list.am:


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@142604 268f45cc-cd09-0410-ab3c-d52691b4dbfc