Prototype adapter XInput feasibility

adapter_host_probe_state.h

@@ -0,0 +1,30 @@
+#pragma once
+
+#include <stdint.h>
+
+class AdapterHostProbeState {
+  public:
+    static constexpr uint32_t kRebootDelayMs = 100;
+
+    void note_ms_os_string() { saw_ms_os_string_ = true; }
+
+    void note_ms_compat_id_request(uint32_t now_ms) {
+        if (!saw_ms_os_string_) {
+            return;
+        }
+        confirmed_windows_ = true;
+        reboot_deadline_ms_ = now_ms + kRebootDelayMs;
+    }
+
+    bool windows_confirmed() const { return confirmed_windows_; }
+
+    bool should_reboot(uint32_t now_ms) const {
+        return confirmed_windows_ &&
+               static_cast<int32_t>(now_ms - reboot_deadline_ms_) >= 0;
+    }
+
+  private:
+    uint32_t reboot_deadline_ms_ = 0;
+    bool saw_ms_os_string_ = false;
+    bool confirmed_windows_ = false;
+};