Merge pull request #514 from Unity-Technologies/Branch_FixDebugWindow

Branch fix debug window

ScriptableRenderPipeline/Core/Debugging/DebugMenuManager.cs

             if(m_DebugMenuState != null && m_DebugMenuStateDirty)
             {
                 m_DebugMenuStateDirty = false;
-                m_DebugMenuState.UpdateAllDebugItems();
+                m_DebugMenuState.ReInitializeDebugItemStates();
             }
 
             m_DebugMenuUI.Update();

ScriptableRenderPipeline/Core/Debugging/DebugMenuState.cs

 #if UNITY_EDITOR
             UnityEditor.Undo.undoRedoPerformed += OnUndoRedoPerformed;
 #endif
+            DebugMenuManager.instance.SetDebugMenuState(this);
+        }
+
+        public void OnDisable()
+        {
+            DebugMenuManager.instance.SetDebugMenuState(null);
+
+#if UNITY_EDITOR
+            UnityEditor.Undo.undoRedoPerformed -= OnUndoRedoPerformed;
+#endif
+        }
+
+        public void ReInitializeDebugItemStates()
+        {
+            CleanUp();
             // Populate item states
             DebugMenuManager dmm = DebugMenuManager.instance;
             for (int panelIdx = 0; panelIdx < dmm.panelCount; ++panelIdx)
                     if (debugItemState == null)
                     {
                         debugItemState = item.handler.CreateDebugItemState();
-                        if(debugItemState != null)
+                        if (debugItemState != null)
                         {
                             debugItemState.hideFlags = HideFlags.DontSave;
                             debugItemState.Initialize(item);
                 }
             }
 
-            DebugMenuManager.instance.SetDebugMenuState(this);
+            UpdateAllDebugItems();
-        public void OnDisable()
+        private void CleanUp()
-#if UNITY_EDITOR
-            UnityEditor.Undo.undoRedoPerformed -= OnUndoRedoPerformed;
-#endif
+            foreach (var item in m_ItemStateList)
+            {
+                Object.DestroyImmediate(item);
+            }
+
+            m_ItemStateList.Clear();
-            foreach(var item in m_ItemStateList)
-            {
-                Object.DestroyImmediate(item);
-            }
+            CleanUp();
         }
 
         void OnUndoRedoPerformed()
 #endif
         }
 
-        public void AddDebugItemState(DebugItemState state)
+        private void AddDebugItemState(DebugItemState state)
         {
             m_ItemStateList.Add(state);
         }
             return m_ItemStateList.Find(x => x.itemName == item.name && x.panelName == item.panelName);
         }
 
-        public void UpdateAllDebugItems()
+        private void UpdateAllDebugItems()
         {
             foreach (var itemState in m_ItemStateList)
             {

ScriptableRenderPipeline/Core/Debugging/Editor/DebugMenuEditor.cs

         {
             DebugItemState debugItemState = m_DebugMenuState.FindDebugItemState(item);
 
-            UnityEditor.Undo.RecordObject(debugItemState, "DebugMenu State Update");
-            debugItemState.SetValue(item.GetValue());
-            EditorUtility.SetDirty(m_DebugMenuState);
+            if(debugItemState != null)
+            {
+                UnityEditor.Undo.RecordObject(debugItemState, "DebugMenu State Update");
+                debugItemState.SetValue(item.GetValue());
+                EditorUtility.SetDirty(m_DebugMenuState);
+            }
         }
 
         void OnGUI()