|HDRenderPipeEditor] Dispose created HDRenderPipeline instance when the HDRenderPipelineAsset was modified in the Editor

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Editor/HDRenderPipelineInspector.cs

             m_FrameSettingsUI.Reset(serializedFrameSettings, Repaint);
         }
 
-        static void HackSetDirty(RenderPipelineAsset asset)
-        {
-            EditorUtility.SetDirty(asset);
-            var method = typeof(RenderPipelineAsset).GetMethod("OnValidate", BindingFlags.FlattenHierarchy | BindingFlags.NonPublic | BindingFlags.Instance);
-            if (method != null)
-                method.Invoke(asset, new object[0]);
-        }
-
-            EditorGUI.BeginChangeCheck();
             EditorGUILayout.PropertyField(m_SpotCookieSize, s_Styles.spotCookieSize);
             EditorGUILayout.PropertyField(m_PointCookieSize, s_Styles.pointCookieSize);
             EditorGUILayout.PropertyField(m_ReflectionCubemapSize, s_Styles.reflectionCubemapSize);
             EditorGUILayout.PropertyField(m_SkyLightingOverrideLayerMask, s_Styles.skyLightingOverride);
-            if (EditorGUI.EndChangeCheck())
-            {
-                HackSetDirty(hdAsset); // Repaint
-            }
             EditorGUI.indentLevel--;
         }
 
             EditorGUILayout.LabelField(s_Styles.renderingSettingsLabel);
             EditorGUI.indentLevel++;
-            EditorGUI.BeginChangeCheck();
-            if (EditorGUI.EndChangeCheck())
-            {
-                HackSetDirty(hdAsset); // Repaint
-            }
             EditorGUI.indentLevel--;
         }
 
             EditorGUILayout.LabelField(s_Styles.shadowSettings);
             EditorGUI.indentLevel++;
-            EditorGUI.BeginChangeCheck();
-            if (EditorGUI.EndChangeCheck())
-            {
-                HackSetDirty(hdAsset); // Repaint
-            }
             EditorGUI.indentLevel--;
         }
 

ScriptableRenderPipeline/HDRenderPipeline/HDRP/HDRenderPipelineAsset.cs

             // Modification of defaultFrameSettings in the inspector will call OnValidate().
             // We do a copy of the settings to those effectively used
             serializedFrameSettings.CopyTo(m_FrameSettings);
+
+            // All instance created in the editor have obsolete settings
+            // So we must dispose them
+            DestroyCreatedInstances();
         }
 
         // Store the various RenderPipelineSettings for each platform (for now only one)