Add IPC for DNS host address resolution.

content/renderer/p2p/host_address_request.h

Index: content/renderer/p2p/host_address_request.h
diff --git a/content/renderer/p2p/host_address_request.h b/content/renderer/p2p/host_address_request.h
new file mode 100644
index 0000000000000000000000000000000000000000..14a5ae0a6a7993f2f742b01fa5ace3b4989e8859
--- /dev/null
+++ b/content/renderer/p2p/host_address_request.h
@@ -0,0 +1,68 @@
+// Copyright (c) 2011 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_P2P_HOST_ADDRESS_REQUEST_H_
+#define CONTENT_RENDERER_P2P_HOST_ADDRESS_REQUEST_H_
+
+#include <string>
+
+#include "base/callback.h"
+#include "base/memory/ref_counted.h"
+#include "net/base/net_util.h"
+
+namespace base {
+class MessageLoopProxy;
+}  // namespace base
+
+class P2PSocketDispatcher;
+
+class P2PHostAddressRequest :
+    public base::RefCountedThreadSafe<P2PHostAddressRequest>  {
+ public:
+  typedef base::Callback<void(const net::IPAddressNumber&)> DoneCallback;
+
+  P2PHostAddressRequest(P2PSocketDispatcher* dispatcher);
+
+  // Sends host address request.
+  void Request(const std::string& host_name,
+               const DoneCallback& done_callback);
+
+  // Cancels the request. The callback passed to Request() will not be
+  // called after Cancel() is called.
+  void Cancel();
+
+ private:
+  enum State {
+    STATE_CREATED,
+    STATE_SENT,
+    STATE_FINISHED,
+  };
+
+  friend class P2PSocketDispatcher;
+
+  friend class base::RefCountedThreadSafe<P2PHostAddressRequest>;
+  virtual ~P2PHostAddressRequest();
+
+  void DoSendRequest(const std::string& host_name,
+                     const DoneCallback& done_callback);
+  void DoUnregister();
+  void OnResponse(const net::IPAddressNumber& address);
+  void DeliverResponse(const net::IPAddressNumber& address);
+
+  P2PSocketDispatcher* dispatcher_;
+  scoped_refptr<base::MessageLoopProxy> ipc_message_loop_;
+  scoped_refptr<base::MessageLoopProxy> delegate_message_loop_;
+  DoneCallback done_callback_;
+
+  // State must be accessed from delegate thread only.
+  State state_;
+
+  // Accessed on the IPC thread only.
+  int32 request_id_;
+  bool registered_;
+
+  DISALLOW_COPY_AND_ASSIGN(P2PHostAddressRequest);
+};
+
+#endif  // CONTENT_RENDERER_P2P_HOST_ADDRESS_REQUEST_H_