Use camelCase not under_score, I forgot it's coffee script.

renderer/api/lib/ipc.coffee

@@ -1,5 +1,5 @@
 EventEmitter = require('events').EventEmitter
-ipc = process.atom_binding('ipc')
+ipc = process.atomBinding('ipc')
 
 class Ipc extends EventEmitter
   constructor: ->

renderer/api/lib/remote.coffee

@@ -1,5 +1,5 @@
 ipc = require 'ipc'
-v8_util = process.atom_binding 'v8_util'
+v8_util = process.atomBinding 'v8_util'
 
 # Transform the description of value into a value or delegate object.
 metaToValue = (meta) ->