Keyboard Lock Host implementation

components/keyboard_lock/active_key_event_filter.h

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef COMPONENTS_KEYBOARD_LOCK_ACTIVE_KEY_EVENT_FILTER_H_
+#define COMPONENTS_KEYBOARD_LOCK_ACTIVE_KEY_EVENT_FILTER_H_
+
+#include "components/keyboard_lock/key_event_filter.h"
+
+namespace keyboard_lock {
+
+class ActiveKeyEventFilterTracker;
+
+// A KeyEventFilter implementation to forward the key events to the active
+// KeyEventFilter in |tracker|.
+class ActiveKeyEventFilter final : public KeyEventFilter {
+ public:
+  // |tracker| must outlive |this|.
+  ActiveKeyEventFilter(const ActiveKeyEventFilterTracker* tracker);
+  ~ActiveKeyEventFilter() override;
+
+ private:
+  // KeyEventFilter implementations.
+  bool OnKeyDown(ui::KeyboardCode code, int flags) override;
+  bool OnKeyUp(ui::KeyboardCode code, int flags) override;
+
+  const ActiveKeyEventFilterTracker* const tracker_;
+};
+
+}  // namespace keyboard_lock
+
+#endif  // COMPONENTS_KEYBOARD_LOCK_ACTIVE_KEY_EVENT_FILTER_H_