Keyboard Lock Host implementation

components/keyboard_lock/key_hook_activator.h

Index: components/keyboard_lock/key_hook_activator.h
diff --git a/components/keyboard_lock/key_hook_activator.h b/components/keyboard_lock/key_hook_activator.h
new file mode 100644
index 0000000000000000000000000000000000000000..45d54d5f598e5958b7b16c01ac31b23c89847b70
--- /dev/null
+++ b/components/keyboard_lock/key_hook_activator.h
@@ -0,0 +1,37 @@
+// 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_HOOK_ACTIVATOR_H_
+#define COMPONENTS_KEYBOARD_LOCK_KEY_HOOK_ACTIVATOR_H_
+
+#include <vector>
+
+#include "base/callback.h"
+#include "components/keyboard_lock/key_hook.h"
+#include "ui/events/keycodes/keyboard_codes.h"
+
+namespace keyboard_lock {
+
+// An interface to store all registered key codes and register or unregister
+// them with one Activate() or Deactivate() function call.
+// The implementation needs to guarantee the thread-safety of Activate() and
+// Deactivate() functions, which may be executed in both UI thread and
+// network thread.
+class KeyHookActivator : public KeyHook {
+ public:
+  KeyHookActivator() = default;
+  ~KeyHookActivator() override = default;
+
+  // Meaning of |on_result| is same as the one in KeyHook::RegisterKey().
+
+  // Enables all registered key codes.
+  virtual void Activate(base::Callback<void(bool)> on_result) = 0;
+
+  // Disables all registered key codes.
+  virtual void Deactivate(base::Callback<void(bool)> on_result) = 0;
+};
+
+}  // namespace keyboard_lock
+
+#endif  // COMPONENTS_KEYBOARD_LOCK_KEY_HOOK_ACTIVATOR_H_