Put window.onerror method in the window file.

index.html

@@ -12,10 +12,6 @@
 
 <script src='src/stdlib/require.js'></script>
 <script>
-  window.onerror = function() {
-    window.showConsole(true)
-  }
-
   window.onload = function() {
     require('startup');
   }

src/atom/window.coffee

@@ -8,6 +8,7 @@ _ = require 'underscore'
 #   window:load - Same as window.onLoad. Final event of app startup.
 windowAdditions =
   url: $atomController.url?.toString()
+  onerror: -> @showConsole true
 
   startup: ->
     if not @resource = atom.router.open @url