Keyboard Lock Host implementation

components/keyboard_lock/register_once_key_hook.cc

Index: components/keyboard_lock/register_once_key_hook.cc
diff --git a/components/keyboard_lock/register_once_key_hook.cc b/components/keyboard_lock/register_once_key_hook.cc
new file mode 100644
index 0000000000000000000000000000000000000000..c3da34ca48639bf39c4e4b7418f65ad92bd43337
--- /dev/null
+++ b/components/keyboard_lock/register_once_key_hook.cc
@@ -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.
+
+#include "components/keyboard_lock/register_once_key_hook.h"
+
+namespace keyboard_lock {
+
+RegisterOnceKeyHook::RegisterOnceKeyHook() = default;
+RegisterOnceKeyHook::~RegisterOnceKeyHook() = default;
+
+bool RegisterOnceKeyHook::RegisterKey(
+    const std::vector<ui::KeyboardCode>& codes) {
+  bool result = false;
+  if (count_ == 0) {
+    result = Register();
+  } else {
+    result = true;
+  }
+  count_ += codes.size();
+  return result;
+}
+
+bool RegisterOnceKeyHook::UnregisterKey(
+    const std::vector<ui::KeyboardCode>& codes) {
+  bool result = false;
+  if (count_ <= static_cast<int>(codes.size())) {
+    result = Unregister();
+    count_ = 0;
+  } else {
+    result = true;
+    count_ -= codes.size();
+  }
+  return result;
+}
+
+}  // namespace keyboard_lock