Use GuestWindowManager to mange windows created by window.open

atom/browser/api/atom_api_web_contents.cc

@@ -441,6 +441,7 @@ mate::ObjectTemplateBuilder WebContents::GetObjectTemplateBuilder(
         .SetMethod("_send", &WebContents::SendIPCMessage)
         .SetMethod("setAutoSize", &WebContents::SetAutoSize)
         .SetMethod("setAllowTransparency", &WebContents::SetAllowTransparency)
+        .SetMethod("isGuest", &WebContents::is_guest)
         .Build());
 
   return mate::ObjectTemplateBuilder(

atom/browser/api/lib/web-contents.coffee

@@ -2,10 +2,6 @@ EventEmitter = require('events').EventEmitter
 binding = process.atomBinding 'web_contents'
 ipc = require 'ipc'
 
-# Routed window.open messages.
-ipc.on 'ATOM_SHELL_WEB_CONTENTS_WINDOW_OPEN', (event, args...) ->
-  event.sender.emit 'new-window', event, args...
-
 module.exports.wrap = (webContents) ->
   return null unless webContents.isAlive()