Stock calls Frame.SetControlsItems once per control on every re-render
of a window's controls (~12 identical calls per window and scene-graph
update); each replaces three MobX arrays and re-renders the bar. The
wrapper now skips the stock setter when the (re-partitioned) lists equal
the frame's current ones, and reads each action's icon once per call
(protoForSteam is recomputed on every untracked read).
Pierre Kisters
885a97aa59