Update thread annotiation macros in modules to use RTC_ prefix

webrtc/modules/rtp_rtcp/include/rtp_payload_registry.h

Index: webrtc/modules/rtp_rtcp/include/rtp_payload_registry.h
diff --git a/webrtc/modules/rtp_rtcp/include/rtp_payload_registry.h b/webrtc/modules/rtp_rtcp/include/rtp_payload_registry.h
index eb552b84e1ef3affd22727392f0b9c83c9239d41..a84e2d35cf8408ef1ca427f1c115dc6776c56600 100644
--- a/webrtc/modules/rtp_rtcp/include/rtp_payload_registry.h
+++ b/webrtc/modules/rtp_rtcp/include/rtp_payload_registry.h
@@ -126,13 +126,14 @@ class RTPPayloadRegistry {
   uint32_t ssrc_rtx_;
   // Only warn once per payload type, if an RTX packet is received but
   // no associated payload type found in |rtx_payload_type_map_|.
-  std::set<int> payload_types_with_suppressed_warnings_ GUARDED_BY(crit_sect_);
+  std::set<int> payload_types_with_suppressed_warnings_
+      RTC_GUARDED_BY(crit_sect_);
 
   // As a first step in splitting this class up in separate cases for audio and
   // video, DCHECK that no instance is used for both audio and video.
 #if RTC_DCHECK_IS_ON
-  bool used_for_audio_ GUARDED_BY(crit_sect_) = false;
-  bool used_for_video_ GUARDED_BY(crit_sect_) = false;
+  bool used_for_audio_ RTC_GUARDED_BY(crit_sect_) = false;
+  bool used_for_video_ RTC_GUARDED_BY(crit_sect_) = false;
 #endif
 };