Add ui devtools server

ui/devtools/devtools_client.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.
+
+#ifndef UI_DEVTOOLS_DEVTOOLS_CLIENT_H_
+#define UI_DEVTOOLS_DEVTOOLS_CLIENT_H_
+
+#include <string>
+
+#include "ui/devtools/DOM.h"
+#include "ui/devtools/Forward.h"
+#include "ui/devtools/Protocol.h"
+#include "ui/devtools/string_util.h"
+
+namespace ui {
+namespace devtools {
+
+class UiDevToolsServer;
+
+// Every UI component that wants to be inspectable must instantiate
+// this class and attach the corresponding backends/frontends (i.e: DOM, CSS,
+// etc). This client is then attached to the UiDevToolsServer and all messages
+// from this client are sent over the web socket owned by the server.
+class UiDevToolsClient : public protocol::FrontendChannel {
+ public:
+  static const int kNotConnected = -1;
+
+  UiDevToolsClient(const String& name, UiDevToolsServer* server);

[sadrul, 2016/10/18 20:29:37]

Let's use const std::string& here. (you probably don't need the strint_util.h
include above)

[Sarmad Hashmi, 2016/10/19 23:56:02]

Done.

+  ~UiDevToolsClient() override;
+
+  void AddDOMBackend(std::unique_ptr<protocol::DOM::Backend> dom_backend);
+  void Dispatch(const String& data);
+
+  bool connected() const;
+  void set_connection_id(int connection_id);
+  std::string name() const;

[sadrul, 2016/10/18 20:29:37]

return a const-ref as well, i.e.:
  const std::string& name() const { return name_; }

[Sarmad Hashmi, 2016/10/19 23:56:02]

Done.

+
+ private:
+  // protocol::FrontendChannel
+  void sendProtocolResponse(int callId, const String& message) override;
+  void sendProtocolNotification(const String& message) override;
+  void flushProtocolNotifications() override;
+
+  std::string name_;
+  int connection_id_;
+
+  std::unique_ptr<protocol::DOM::Backend> dom_backend_;
+  protocol::UberDispatcher dispatcher_;
+  UiDevToolsServer* server_;
+
+  DISALLOW_COPY_AND_ASSIGN(UiDevToolsClient);
+};
+
+}  // namespace devtools
+}  // namespace ui
+
+#endif  // UI_DEVTOOLS_DEVTOOLS_CLIENT_H_