win: Remove dead menu code.

atom/browser/api/lib/menu-item.coffee

@@ -38,14 +38,6 @@ class MenuItem
   overrideProperty: (name, defaultValue=null) ->
     this[name] ?= defaultValue
 
-    # Update states when property is changed on Windows.
-    return unless process.platform is 'win32'
-    v8Util.setHiddenValue this, name, this[name]
-    Object.defineProperty this, name,
-      enumerable: true
-      get: => v8Util.getHiddenValue this, name
-      set: (val) => v8Util.setHiddenValue this, name, val
-
   overrideReadOnlyProperty: (name, defaultValue=null) ->
     this[name] ?= defaultValue
     Object.defineProperty this, name,

atom/browser/api/lib/menu.coffee

@@ -87,10 +87,6 @@ Menu::insert = (pos, item) ->
   @items.splice pos, 0, item
   @commandsMap[item.commandId] = item
 
-Menu::attachToWindow = (window) ->
-  @_callMenuWillShow() if process.platform is 'win32'
-  @_attachToWindow window
-
 # Force menuWillShow to be called
 Menu::_callMenuWillShow = ->
   @delegate?.menuWillShow()