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_unittest.cc

@@ -0,0 +1,53 @@
+/*
+ *  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.
+ */
+
+#include <memory>
+#include <string>
+
+#include "webrtc/base/asyncudpsocket.h"
+#include "webrtc/base/gunit.h"
+#include "webrtc/base/physicalsocketserver.h"
+#include "webrtc/base/virtualsocketserver.h"
+
+namespace rtc {
+
+class AsyncUdpSocketTest
+    : public testing::Test,
+      public sigslot::has_slots<> {
+ public:
+  AsyncUdpSocketTest()
+      : pss_(new rtc::PhysicalSocketServer),
+        vss_(new rtc::VirtualSocketServer(pss_.get())),
+        socket_(vss_->CreateAsyncSocket(SOCK_DGRAM)),
+        udp_socket_(new AsyncUDPSocket(socket_)),
+        ready_to_send_(false) {
+    udp_socket_->SignalReadyToSend.connect(this,
+                                           &AsyncUdpSocketTest::OnReadyToSend);
+  }
+
+  void OnReadyToSend(rtc::AsyncPacketSocket* socket) {
+    ready_to_send_ = true;
+  }
+
+ protected:
+  std::unique_ptr<PhysicalSocketServer> pss_;
+  std::unique_ptr<VirtualSocketServer> vss_;
+  AsyncSocket* socket_;
+  std::unique_ptr<AsyncUDPSocket> udp_socket_;
+  bool ready_to_send_;
+};
+
+TEST_F(AsyncUdpSocketTest, OnWriteEvent) {
+  EXPECT_FALSE(ready_to_send_);
+  socket_->SignalWriteEvent(socket_);
+  EXPECT_TRUE(ready_to_send_);
+}
+
+}  // namespace rtc