title: Unity in editor mode, OnGUI not called every frame
body: <p>I've created a button which is activated by selecting the option from the gameobject menu. This button does nothing but disappear upon clicking on it. However, theres always a delay between clicking on the button and it disappearing from the screen in game view. Can anyone help me with this please?</p>
  
  <pre><code>    [ExecuteInEditMode]
      public class TestButton : MonoBehaviour
      {
         private static bool _setButton = false;
  
         [MenuItem("GameObject/TestButton")] 
         static void Init()
         {
          _setButton = true;
         }
  
         void OnGUI()
         {
          GUILayout.BeginArea(new Rect(100, 0, 300, 100));
          if (_setButton)
          {
             if (GUILayout.Button("TEST BUTTON"))
             {
                _setButton = false;           
             }
             GUILayout.EndArea();
          }
         }
  }
  </code></pre>