Update thread annotiation macros in modules to use RTC_ prefix

webrtc/modules/video_coding/utility/quality_scaler.h

Index: webrtc/modules/video_coding/utility/quality_scaler.h
diff --git a/webrtc/modules/video_coding/utility/quality_scaler.h b/webrtc/modules/video_coding/utility/quality_scaler.h
index 25d39cc986ab84e7860ec3bec2c3b705b3629b66..abe6d72bd43b605fe32449af253b07c3aa46ae73 100644
--- a/webrtc/modules/video_coding/utility/quality_scaler.h
+++ b/webrtc/modules/video_coding/utility/quality_scaler.h
@@ -71,16 +71,16 @@ class QualityScaler {
   void ReportQPHigh();
   int64_t GetSamplingPeriodMs() const;
 
-  CheckQPTask* check_qp_task_ GUARDED_BY(&task_checker_);
-  AdaptationObserverInterface* const observer_ GUARDED_BY(&task_checker_);
+  CheckQPTask* check_qp_task_ RTC_GUARDED_BY(&task_checker_);
+  AdaptationObserverInterface* const observer_ RTC_GUARDED_BY(&task_checker_);
   rtc::SequencedTaskChecker task_checker_;
 
   const int64_t sampling_period_ms_;
-  bool fast_rampup_ GUARDED_BY(&task_checker_);
-  MovingAverage average_qp_ GUARDED_BY(&task_checker_);
-  MovingAverage framedrop_percent_ GUARDED_BY(&task_checker_);
+  bool fast_rampup_ RTC_GUARDED_BY(&task_checker_);
+  MovingAverage average_qp_ RTC_GUARDED_BY(&task_checker_);
+  MovingAverage framedrop_percent_ RTC_GUARDED_BY(&task_checker_);
 
-  VideoEncoder::QpThresholds thresholds_ GUARDED_BY(&task_checker_);
+  VideoEncoder::QpThresholds thresholds_ RTC_GUARDED_BY(&task_checker_);
 };
 }  // namespace webrtc