Fixed Inspector Exception when drawing HDRenderLoop

Assets/BasicRenderLoopTutorial/BasicRenderLoop.cs

 
     private ShaderPassName shaderPassBasic;
 
+    public void OnEnable()
+    {
+        Rebuild();
+    }
+
     public override void Initialize()
     {
         shaderPassBasic = new ShaderPassName("BasicPass");

Assets/ScriptableRenderLoop/HDRenderLoop/HDRenderLoop.cs

         TextureCache2D m_CookieTexArray;
         TextureCacheCubemap m_CubeCookieTexArray;
 
-        void OnValidate()
+        private void OnEnable()
+            // TODO: Design workaround for OnValidate being missing on ScriptableObject
+            Rebuild();
+        }
+
+        private void OnDisable()
+        {
+            // TODO: Rework ScriptableRenderLoop Lifecycle 
+            //CleanUp();
         }
 
         public override void Rebuild()

Assets/ScriptableRenderLoop/fptl/FptlLighting.cs

             Rebuild();
         }
 
+        private void OnEnable()
+        {
+            Rebuild();
+        }
+
-            CleanUp();
+            // TODO: Rework ScriptableRenderLoop Lifecycle
+            //CleanUp();
         }
 
         public override void CleanUp()
             }
 
             ClearComputeBuffers();
-        }
-
-        void OnValidate()
-        {
-            Rebuild();
         }
 
         void ClearComputeBuffers()