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    // A WM_* message is available.
    // If a parent child relationship exists between windows across threads
    // then their thread inputs are implicitly attached.
    // This causes the MsgWaitForMultipleObjectsEx API to return indicating
    // that messages are ready for processing (Specifically, mouse messages
    // intended for the child window may appear if the child window has
    // capture).
    // The subsequent PeekMessages call may fail to return any messages thus
    // causing us to enter a tight loop at times.
    // The WaitMessage call below is a workaround to give the child window
    // some time to process its input messages.
    MSG msg = {0};
    DWORD queue_status = GetQueueStatus(QS_MOUSE);
    if (HIWORD(queue_status) & QS_MOUSE &&
        !PeekMessage(&msg, NULL, WM_MOUSEFIRST, WM_MOUSELAST, PM_NOREMOVE)) {
      WaitMessage();
    }