Merge pull request #391 from Unity-Technologies/callback-fix

Fix #390

Author: Chman

PostProcessing/Runtime/PostProcessLayer.cs

@@ -118,6 +118,11 @@ void OnEnable()
             m_TargetPool = new TargetPool();
 
             debugLayer.OnEnable();
+
+            if (RuntimeUtilities.scriptableRenderPipelineActive)
+                return;
+
+            CheckInitLegacy();
         }
 
         void CheckInitLegacy()