Remove old WebSocket implementation from content/

content/common/socket_stream_handle_data.h

-// Copyright (c) 2012 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 CONTENT_RENDERER_SOCKET_STREAM_HANDLE_DATA_H_
-#define CONTENT_RENDERER_SOCKET_STREAM_HANDLE_DATA_H_
-
-#include "base/supports_user_data.h"
-#include "content/common/content_export.h"
-
-namespace content {
-
-// User data stored in each WebSocketStreamHandleImpl.
-class SocketStreamHandleData : public base::SupportsUserData::Data {
- public:
-  explicit SocketStreamHandleData(int render_frame_id)
-      : render_frame_id_(render_frame_id) {}
-  ~SocketStreamHandleData() override {}
-
-  int render_frame_id() const { return render_frame_id_; }
-
- private:
-  int render_frame_id_;
-
-  DISALLOW_COPY_AND_ASSIGN(SocketStreamHandleData);
-};
-
-}  // namespace content
-
-#endif  // CONTENT_RENDERER_SOCKET_STREAM_HANDLE_DATA_H_