Use ipc to store and retrieve windowState

I'll want to change the interface in the future. For now I am trying
to keep the code as simple and small as possible.

src/app/atom.coffee

@@ -2,6 +2,7 @@ fsUtils = require 'fs-utils'
 _ = require 'underscore'
 Package = require 'package'
 Theme = require 'theme'
+ipc = require 'ipc'
 
 window.atom =
   exitWhenDone: window.location.params.exitWhenDone
@@ -244,7 +245,7 @@ window.atom =
   setWindowState: (keyPath, value) ->
     windowState = @getWindowState()
     _.setValueForKeyPath(windowState, keyPath, value)
-    $native.setWindowState(JSON.stringify(windowState))
+    ipc.sendChannel('window-state', JSON.stringify(windowState))
     windowState
 
   getWindowState: (keyPath) ->
@@ -255,7 +256,7 @@ window.atom =
       windowState
 
   getInMemoryWindowState: ->
-    inMemoryState = $native.getWindowState()
+    inMemoryState = ipc.sendChannelSync('window-state')
     if inMemoryState.length > 0
       inMemoryState
     else

src/main.coffee

@@ -2,12 +2,18 @@ app = require 'app'
 delegate = require 'atom_delegate'
 path = require 'path'
 BrowserWindow = require 'browser_window'
+ipc = require 'ipc'
 
+windowState = {}
 
 # Quit when all windows are closed.
 app.on 'window-all-closed', ->
   app.quit()
 
+ipc.on 'window-state', (event, processId, messageId, message) ->
+  windowState = message unless message == undefined
+  event.result = windowState
+
 class AtomWindow
   @windows = []