WMError doEndDraw(unsigned req_num);
WMError layoutChange(const WMAction &action);
WMError visibilityChange(const WMAction &action);
WMError setSurfaceSize(unsigned surface, const std::string& area);
WMError doEndDraw(unsigned req_num);
WMError layoutChange(const WMAction &action);
WMError visibilityChange(const WMAction &action);
WMError setSurfaceSize(unsigned surface, const std::string& area);