[DevTools] Introduce DevToolsSession.

content/browser/devtools/devtools_session.h

+// Copyright 2016 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 "content/browser/devtools/protocol/forward.h"
+
+namespace content {
+
+class DevToolsAgentHostImpl;
+
+class DevToolsSession : public protocol::FrontendChannel {
+ public:
+  DevToolsSession(DevToolsAgentHostImpl* agent_host, int session_id);
+  ~DevToolsSession() override;
+
+  int session_id() { return session_id_; }
+  protocol::UberDispatcher* dispatcher() { return dispatcher_.get(); }
+
+ private:
+  // protocol::FrontendChannel implementation.
+  void sendProtocolResponse(int call_id, const std::string& message) override;
+  void sendProtocolNotification(const std::string& message) override;
+  void flushProtocolNotifications() override;
+
+  DevToolsAgentHostImpl* agent_host_;
+  int session_id_;
+  std::unique_ptr<protocol::UberDispatcher> dispatcher_;
+};
+
+}  // namespace content