Keyboard Lock Host implementation

components/keyboard_lock/key_event_filter_thread_proxy.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_KEY_EVENT_FILTER_THREAD_PROXY_H_
+#define COMPONENTS_KEYBOARD_LOCK_KEY_EVENT_FILTER_THREAD_PROXY_H_
+
+#include <memory>
+
+#include "base/memory/ref_counted.h"
+#include "components/keyboard_lock/key_event_filter.h"
+
+namespace base {
+class SingleThreadTaskRunner;
+}  // namespace base
+
+namespace keyboard_lock {
+
+// TODO(zijiehe): Is this class necessary? i.e. Is it needed to forward
+// RenderWidgetHost::ForwardKeyboardEvent() to network thread?
+// An implementation of KeyEventFilter to forward all requests to |runner| and
+// |filter|.
+class KeyEventFilterThreadProxy : public KeyEventFilter {
+ public:
+  KeyEventFilterThreadProxy(
+      scoped_refptr<base::SingleThreadTaskRunner> runner,
+      std::unique_ptr<KeyEventFilter> filter);
+  ~KeyEventFilterThreadProxy() override;
+
+ private:
+  // KeyEventFilter implementations
+  // Because the requests will be sent to a different thread, these functions
+  // always return true.
+  bool OnKeyDown(ui::KeyboardCode code, int flags) override;
+  bool OnKeyUp(ui::KeyboardCode code, int flags) override;
+
+  const scoped_refptr<base::SingleThreadTaskRunner> runner_;
+  const std::unique_ptr<KeyEventFilter> filter_;
+};
+
+}  // namespace keyboard_lock
+
+#endif  // COMPONENTS_KEYBOARD_LOCK_KEY_EVENT_FILTER_THREAD_PROXY_H_