[NaCl SDK] nacl_io: Add flow control the JavaScript pipes.

native_client_sdk/src/libraries/nacl_io/library.dsc

 {
   'TOOLS': ['bionic', 'newlib', 'glibc', 'pnacl', 'linux'],
   'SEARCH': [
     '.',
     'pepper',
     '../third_party/newlib-extras',
     'include',
   ],
   'TARGETS': [
     {
+      'DEFINES': ['NACL_IO_LOGGING=0'],
       'NAME' : 'nacl_io',
       'TYPE' : 'lib',
       'SOURCES' : [
         "devfs/dev_fs.cc",
+        "devfs/jspipe_event_emitter.cc",
         "devfs/jspipe_node.cc",
         "devfs/tty_event_emitter.cc",
         "devfs/tty_node.cc",
         "dir_node.cc",
         "event_emitter.cc",
         "event_listener.cc",
         "fifo_char.cc",
         "filesystem.cc",
         "fusefs/fuse_fs.cc",
         "fusefs/fuse_fs_factory.cc",
@@ skipping 130 matching lines @@
         "syscalls/utime.c",
         "syscalls/utimes.c",
       ],
     }
   ],
   'HEADERS': [
     {
       'FILES': [
         "char_node.h",
         "devfs/dev_fs.h",
+        "devfs/jspipe_event_emitter.h",
         "devfs/jspipe_node.h",
         "devfs/tty_event_emitter.h",
         "devfs/tty_node.h",
         "dir_node.h",
         "error.h",
         "event_emitter.h",
         "event_listener.h",
         "fifo_char.h",
         "fifo_interface.h",
         "fifo_null.h",
@@ skipping 105 matching lines @@
         "all_interfaces.h",
         "define_empty_macros.h",
         "undef_macros.h",
       ],
       'DEST': 'include/nacl_io/pepper',
     }
   ],
   'DEST': 'src',
   'NAME': 'nacl_io',
 }