Services: Add a WebSocket service

The WebSocket service isolates communication with a WebSocket to its
own isolated process. Similar to other isolating services, it has its
own user and group.

Userland/Libraries/LibProtocol/WebSocket.cpp

@@ -0,0 +1,70 @@
+/*
+ * Copyright (c) 2021, Dex♪ <dexes.ttp@gmail.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibProtocol/WebSocket.h>
+#include <LibProtocol/WebSocketClient.h>
+
+namespace Protocol {
+
+WebSocket::WebSocket(WebSocketClient& client, i32 connection_id)
+    : m_client(client)
+    , m_connection_id(connection_id)
+{
+}
+
+WebSocket::ReadyState WebSocket::ready_state()
+{
+    return (WebSocket::ReadyState)m_client->ready_state({}, *this);
+}
+
+void WebSocket::send(ByteBuffer binary_or_text_message, bool is_text)
+{
+    m_client->send({}, *this, move(binary_or_text_message), is_text);
+}
+
+void WebSocket::send(StringView text_message)
+{
+    send(ByteBuffer::copy(text_message.bytes()), true);
+}
+
+void WebSocket::close(u16 code, String reason)
+{
+    m_client->close({}, *this, code, move(reason));
+}
+
+void WebSocket::did_open(Badge<WebSocketClient>)
+{
+    if (on_open)
+        on_open();
+}
+
+void WebSocket::did_receive(Badge<WebSocketClient>, ByteBuffer data, bool is_text)
+{
+    if (on_message)
+        on_message(WebSocket::Message { move(data), is_text });
+}
+
+void WebSocket::did_error(Badge<WebSocketClient>, i32 error_code)
+{
+    if (on_error)
+        on_error((WebSocket::Error)error_code);
+}
+
+void WebSocket::did_close(Badge<WebSocketClient>, u16 code, String reason, bool was_clean)
+{
+    if (on_close)
+        on_close(code, move(reason), was_clean);
+}
+
+void WebSocket::did_request_certificates(Badge<WebSocketClient>)
+{
+    if (on_certificate_requested) {
+        auto result = on_certificate_requested();
+        if (!m_client->set_certificate({}, *this, result.certificate, result.key))
+            dbgln("WebSocket: set_certificate failed");
+    }
+}
+}