Migrate pc level test metrics to new getStart API

Bug: webrtc:10430
Change-Id: I7555cb967f2e341da43338cb0f8652490992bd31
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/176857
Commit-Queue: Andrey Logvin <landrey@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Reviewed-by: Artem Titov <titovartem@webrtc.org>
Reviewed-by: Henrik Boström <hbos@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#31526}
diff --git a/api/test/video_quality_analyzer_interface.h b/api/test/video_quality_analyzer_interface.h
index 22114be..c5370a7 100644
--- a/api/test/video_quality_analyzer_interface.h
+++ b/api/test/video_quality_analyzer_interface.h
@@ -134,8 +134,9 @@
                               int32_t error_code) {}
   // Will be called every time new stats reports are available for the
   // Peer Connection identified by |pc_label|.
-  void OnStatsReports(const std::string& pc_label,
-                      const StatsReports& stats_reports) override {}
+  void OnStatsReports(
+      absl::string_view pc_label,
+      const rtc::scoped_refptr<const RTCStatsReport>& report) override {}
 
   // Tells analyzer that analysis complete and it should calculate final
   // statistics.