Update thread annotiation macros in rtc_base to use RTC_ prefix

webrtc/rtc_base/task_queue_libevent.cc

 /*
  *  Copyright 2016 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.
  */
 
@@ skipping 132 matching lines @@
   void PrepareReplyTask(scoped_refptr<ReplyTaskOwnerRef> reply_task);
 
   struct QueueContext;
   TaskQueue* const queue_;
   int wakeup_pipe_in_ = -1;
   int wakeup_pipe_out_ = -1;
   event_base* event_base_;
   std::unique_ptr<event> wakeup_event_;
   PlatformThread thread_;
   rtc::CriticalSection pending_lock_;
-  std::list<std::unique_ptr<QueuedTask>> pending_ GUARDED_BY(pending_lock_);
+  std::list<std::unique_ptr<QueuedTask>> pending_ RTC_GUARDED_BY(pending_lock_);
   std::list<scoped_refptr<ReplyTaskOwnerRef>> pending_replies_
-      GUARDED_BY(pending_lock_);
+      RTC_GUARDED_BY(pending_lock_);
 };
 
 struct TaskQueue::Impl::QueueContext {
   explicit QueueContext(TaskQueue::Impl* q) : queue(q), is_active(true) {}
   TaskQueue::Impl* queue;
   bool is_active;
   // Holds a list of events pending timers for cleanup when the loop exits.
   std::list<TimerEvent*> pending_timers_;
 };
 
@@ skipping 350 matching lines @@
   return TaskQueue::impl_->PostTaskAndReply(std::move(task), std::move(reply),
                                             impl_.get());
 }
 
 void TaskQueue::PostDelayedTask(std::unique_ptr<QueuedTask> task,
                                 uint32_t milliseconds) {
   return TaskQueue::impl_->PostDelayedTask(std::move(task), milliseconds);
 }
 
 }  // namespace rtc