Adds a modified copy of talk/base to webrtc/base. It is the first step in migrating talk/base to webrtc/base.

BUG=N/A
R=andrew@webrtc.org, wu@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/12199004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@6107 4adac7df-926f-26a2-2b94-8c16560cd09d

webrtc/base/asyncresolverinterface.h

@@ -0,0 +1,47 @@
+/*
+ *  Copyright 2013 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_BASE_ASYNCRESOLVERINTERFACE_H_
+#define WEBRTC_BASE_ASYNCRESOLVERINTERFACE_H_
+
+#include "webrtc/base/sigslot.h"
+#include "webrtc/base/socketaddress.h"
+
+namespace rtc {
+
+// This interface defines the methods to resolve the address asynchronously.
+class AsyncResolverInterface {
+ public:
+  AsyncResolverInterface() {}
+  virtual ~AsyncResolverInterface() {}
+
+  // Start address resolve process.
+  virtual void Start(const SocketAddress& addr) = 0;
+  // Returns top most resolved address of |family|
+  virtual bool GetResolvedAddress(int family, SocketAddress* addr) const = 0;
+  // Returns error from resolver.
+  virtual int GetError() const = 0;
+  // Delete the resolver.
+  virtual void Destroy(bool wait) = 0;
+  // Returns top most resolved IPv4 address if address is resolved successfully.
+  // Otherwise returns address set in SetAddress.
+  SocketAddress address() const {
+    SocketAddress addr;
+    GetResolvedAddress(AF_INET, &addr);
+    return addr;
+  }
+
+  // This signal is fired when address resolve process is completed.
+  sigslot::signal1<AsyncResolverInterface*> SignalDone;
+};
+
+}  // namespace rtc
+
+#endif