Add mozc dial version.

Co-authored-by: Takashi Toyoshima <toyoshim@google.com>
Co-authored-by: Shun Ikejima <ikejima@google.com>

mozc-dial/firmware/common/usb_hid_keyboard.h

@@ -0,0 +1,49 @@
+// Copyright 2025 Google Inc.
+// Use of this source code is governed by an Apache License that can be found
+// in the LICENSE file.
+
+#ifndef COMMON_USB_HID_KEYBOARD_H_
+#define COMMON_USB_HID_KEYBOARD_H_
+
+#include <cstdint>
+#include <set>
+#include <string>
+#include <vector>
+
+#include "usb_hid_device.h"
+
+class UsbHidKeyboard : public UsbHidDevice {
+ public:
+  UsbHidKeyboard(uint16_t vendor_id,
+                 uint16_t product_id,
+                 uint16_t version,
+                 std::string vendor_name,
+                 std::string product_name,
+                 std::string version_name);
+  UsbHidKeyboard(const UsbHidKeyboard&) = delete;
+  UsbHidKeyboard& operator=(const UsbHidKeyboard&) = delete;
+  ~UsbHidKeyboard() override = default;
+
+  void SetAutoKeyRelease(bool enabled);
+
+  void SetModifiers(uint8_t modifiers);
+  uint8_t GetModifiers() const { return modifiers_; }
+
+  void PressByUsageId(uint8_t usage_id);
+  void ReleaseByUsageId(uint8_t usage_id);
+
+ private:
+  // Implement UsbDevice.
+  void OnCompleteToSend(uint8_t endpoint) override;
+
+  void Report();
+
+  bool auto_key_release_ = false;
+  bool reporting_ = false;
+  bool dirty_ = false;
+  uint8_t modifiers_ = 0;
+  std::set<uint8_t> keycodes_;
+  std::vector<uint8_t> report_;
+};
+
+#endif  // COMMON_USB_HID_KEYBOARD_H_