Update thread annotiation macros in rtc_base to use RTC_ prefix

webrtc/rtc_base/messagequeue.h

Index: webrtc/rtc_base/messagequeue.h
diff --git a/webrtc/rtc_base/messagequeue.h b/webrtc/rtc_base/messagequeue.h
index 2345dce7db5ef79ebcbe30a13d3d05bafb8f6024..79217fb7214fa0d08f129dab2daed2c69f0a46ca 100644
--- a/webrtc/rtc_base/messagequeue.h
+++ b/webrtc/rtc_base/messagequeue.h
@@ -68,13 +68,13 @@ class MessageQueueManager {
 
   static MessageQueueManager* instance_;
   // This list contains all live MessageQueues.
-  std::vector<MessageQueue*> message_queues_ GUARDED_BY(crit_);
+  std::vector<MessageQueue*> message_queues_ RTC_GUARDED_BY(crit_);
 
   // Methods that don't modify the list of message queues may be called in a
   // re-entrant fashion. "processing_" keeps track of the depth of re-entrant
   // calls.
   CriticalSection crit_;
-  size_t processing_ GUARDED_BY(crit_);
+  size_t processing_ RTC_GUARDED_BY(crit_);
 };
 
 // Derive from this for specialized data
@@ -306,9 +306,9 @@ class MessageQueue {
 
   bool fPeekKeep_;
   Message msgPeek_;
-  MessageList msgq_ GUARDED_BY(crit_);
-  PriorityQueue dmsgq_ GUARDED_BY(crit_);
-  uint32_t dmsgq_next_num_ GUARDED_BY(crit_);
+  MessageList msgq_ RTC_GUARDED_BY(crit_);
+  PriorityQueue dmsgq_ RTC_GUARDED_BY(crit_);
+  uint32_t dmsgq_next_num_ RTC_GUARDED_BY(crit_);
   CriticalSection crit_;
   bool fInitialized_;
   bool fDestroyed_;