SetSize() doesn't do anything for MDI children in wxGTK and other ports using TDI version of MDI, but it shouldn't result in an assert from wxTLW::DoMoveWindow() neither, so override DoMoveWindow() in wxTDIChildFrame to avoid it. git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@75523 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775