Squash memory leak
Squash memory leak

svn path=/trunk/hubbub/; revision=5285

adamwight/wmf-parsoid-libhubbub,prepare/netsurf_libhubbub,Achal-Aggarwal/hibbub,servo/libhubbub,adamwight/wmf-parsoid-libhubbub,Achal-Aggarwal/hibbub,prepare/netsurf_libhubbub,prepare/netsurf_libhubbub,adamwight/wmf-parsoid-libhubbub,Achal-Aggarwal/hibbub,prepare/netsurf_libhubbub,adamwight/wmf-parsoid-libhubbub,adamwight/wmf-parsoid-libhubbub,servo/libhubbub,prepare/netsurf_libhubbub,servo/libhubbub,servo/libhubbub,servo/libhubbub,prepare/netsurf_libhubbub,Achal-Aggarwal/hibbub