Add GUARDED_BY in DirectTransport

webrtc/test/direct_transport.h

 /*
  *  Copyright (c) 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_TEST_DIRECT_TRANSPORT_H_
 #define WEBRTC_TEST_DIRECT_TRANSPORT_H_
 
 #include <assert.h>
 
 #include <memory>
 
 #include "webrtc/api/call/transport.h"
 #include "webrtc/call/call.h"
 #include "webrtc/rtc_base/sequenced_task_checker.h"
+#include "webrtc/rtc_base/thread_annotations.h"
 #include "webrtc/test/fake_network_pipe.h"
 #include "webrtc/test/single_threaded_task_queue.h"
 
 namespace webrtc {
 
 class Clock;
 class PacketReceiver;
 
 namespace test {
 
+// Objects of this class are expected to be allocated and destroyed  on the
+// same task-queue - the one that's passed in via the constructor.
 class DirectTransport : public Transport {
  public:
   RTC_DEPRECATED DirectTransport(
       Call* send_call,
       const std::map<uint8_t, MediaType>& payload_type_map);
   RTC_DEPRECATED DirectTransport(
       const FakeNetworkPipe::Config& config,
       Call* send_call,
       const std::map<uint8_t, MediaType>& payload_type_map);
   RTC_DEPRECATED DirectTransport(
@@ skipping 55 matching lines @@
   };
 
   void SendPackets();
 
   Call* const send_call_;
   Clock* const clock_;
 
   // TODO(eladalon): Make |task_queue_| const.
   // https://bugs.chromium.org/p/webrtc/issues/detail?id=8125
   SingleThreadedTaskQueueForTesting* task_queue_;
-  SingleThreadedTaskQueueForTesting::TaskId next_scheduled_task_;
+  SingleThreadedTaskQueueForTesting::TaskId next_scheduled_task_
+      GUARDED_BY(&sequence_checker_);
 
   FakeNetworkPipe fake_network_;
 
   rtc::SequencedTaskChecker sequence_checker_;
 
   // TODO(eladalon): https://bugs.chromium.org/p/webrtc/issues/detail?id=8125
   // Deprecated versions of the ctor don't get the task queue passed in from
   // outside. We'll create one locally for them. This is deprecated, and will
   // be removed as soon as the need for those ctors is removed.
   std::unique_ptr<SingleThreadedTaskQueueForTesting> deprecated_task_queue_;
 };
 }  // namespace test
 }  // namespace webrtc
 
 #endif  // WEBRTC_TEST_DIRECT_TRANSPORT_H_