Fix trunk warnings

com.unity.shadergraph/Editor/Drawing/Controls/GradientControl.cs

 
                 m_Node.owner.owner.RegisterCompleteObjectUndo("Change " + m_Node.name);
                 m_PropertyInfo.SetValue(m_Node, m_GradientObject.gradient, null);
-                Dirty(ChangeType.Repaint);
+                this.MarkDirtyRepaint();
-}
+}