Reland "Move webrtc/{base => rtc_base}" (https://codereview.webrtc.org/2877023002)

Reland the base->rtc_base without adding stub headers (will be
done in follow-up CL). This preserves git blame history of all files.

BUG=webrtc:7634
NOTRY=True
TBR=kwiberg@webrtc.org

Change-Id: Iea3bb6f3f67b8374c96337b63e8f5aa3e6181012
Reviewed-on: https://chromium-review.googlesource.com/554611
Reviewed-by: Henrik Kjellander <kjellander@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#18821}

webrtc/rtc_base/asyncudpsocket.h

@@ -0,0 +1,67 @@
+/*
+ *  Copyright 2004 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_RTC_BASE_ASYNCUDPSOCKET_H_
+#define WEBRTC_RTC_BASE_ASYNCUDPSOCKET_H_
+
+#include <memory>
+
+#include "webrtc/base/asyncpacketsocket.h"
+#include "webrtc/base/socketfactory.h"
+
+namespace rtc {
+
+// Provides the ability to receive packets asynchronously.  Sends are not
+// buffered since it is acceptable to drop packets under high load.
+class AsyncUDPSocket : public AsyncPacketSocket {
+ public:
+  // Binds |socket| and creates AsyncUDPSocket for it. Takes ownership
+  // of |socket|. Returns null if bind() fails (|socket| is destroyed
+  // in that case).
+  static AsyncUDPSocket* Create(AsyncSocket* socket,
+                                const SocketAddress& bind_address);
+  // Creates a new socket for sending asynchronous UDP packets using an
+  // asynchronous socket from the given factory.
+  static AsyncUDPSocket* Create(SocketFactory* factory,
+                                const SocketAddress& bind_address);
+  explicit AsyncUDPSocket(AsyncSocket* socket);
+  ~AsyncUDPSocket() override;
+
+  SocketAddress GetLocalAddress() const override;
+  SocketAddress GetRemoteAddress() const override;
+  int Send(const void* pv,
+           size_t cb,
+           const rtc::PacketOptions& options) override;
+  int SendTo(const void* pv,
+             size_t cb,
+             const SocketAddress& addr,
+             const rtc::PacketOptions& options) override;
+  int Close() override;
+
+  State GetState() const override;
+  int GetOption(Socket::Option opt, int* value) override;
+  int SetOption(Socket::Option opt, int value) override;
+  int GetError() const override;
+  void SetError(int error) override;
+
+ private:
+  // Called when the underlying socket is ready to be read from.
+  void OnReadEvent(AsyncSocket* socket);
+  // Called when the underlying socket is ready to send.
+  void OnWriteEvent(AsyncSocket* socket);
+
+  std::unique_ptr<AsyncSocket> socket_;
+  char* buf_;
+  size_t size_;
+};
+
+}  // namespace rtc
+
+#endif  // WEBRTC_RTC_BASE_ASYNCUDPSOCKET_H_