[NaCl SDK] nacl_io: Remove duplication between passthroughfs and devfs.

native_client_sdk/src/libraries/nacl_io/library.dsc

 {
   'TOOLS': ['newlib', 'glibc', 'bionic', 'pnacl', 'linux'],
   'SEARCH': [
     '.',
     'pepper',
     '../third_party/newlib-extras',
     'include',
   ],
   'TARGETS': [
     {
@@ skipping 30 matching lines @@
         "kernel_wrap_dummy.cc",
         "kernel_wrap_glibc.cc",
         "kernel_wrap_newlib.cc",
         "kernel_wrap_win.cc",
         "log.c",
         "memfs/mem_fs.cc",
         "memfs/mem_fs_node.cc",
         "nacl_io.cc",
         "node.cc",
         "passthroughfs/passthrough_fs.cc",
+        "passthroughfs/real_node.cc",
         "path.cc",
         "pepper_interface.cc",
         "pepper_interface_delegate.cc",
         "pipe/pipe_event_emitter.cc",
         "pipe/pipe_node.cc",
         "real_pepper_interface.cc",
         "socket/fifo_packet.cc",
         "socket/packet.cc",
         "socket/socket_node.cc",
         "socket/tcp_event_emitter.cc",
@@ skipping 145 matching lines @@
         "osmman.h",
         "ossignal.h",
         "ossocket.h",
         "osstat.h",
         "ostermios.h",
         "ostime.h",
         "ostypes.h",
         "osunistd.h",
         "osutime.h",
         "passthroughfs/passthrough_fs.h",
+        "passthroughfs/real_node.h",
         "path.h",
         "pepper_interface_delegate.h",
         "pepper_interface_dummy.h",
         "pepper_interface.h",
         "pipe/pipe_event_emitter.h",
         "pipe/pipe_node.h",
         "real_pepper_interface.h",
         "socket/fifo_packet.h",
         "socket/packet.h",
         "socket/socket_node.h",
@@ skipping 59 matching lines @@
         "all_interfaces.h",
         "define_empty_macros.h",
         "undef_macros.h",
       ],
       'DEST': 'include/nacl_io/pepper',
     }
   ],
   'DEST': 'src',
   'NAME': 'nacl_io',
 }