Relanding Switched main WebRTC browser tests to use a more realistic video

chrome/browser/media/webrtc_browsertest_perf.cc

Index: chrome/browser/media/webrtc_browsertest_perf.cc
diff --git a/chrome/browser/media/webrtc_browsertest_perf.cc b/chrome/browser/media/webrtc_browsertest_perf.cc
index e7839a0f2efe429e0862ca185a8ff9a6a9c2d351..b5ba256c95c0ade25af5d40791681accf4afa285 100644
--- a/chrome/browser/media/webrtc_browsertest_perf.cc
+++ b/chrome/browser/media/webrtc_browsertest_perf.cc
@@ -172,6 +172,8 @@ static std::set<std::string> FindAllSsrcIdentifiers(
   return result;
 }
 
+namespace test {
+
 void PrintBweForVideoMetrics(const base::DictionaryValue& pc_dict) {
   const std::string kBweStatsKey = "bweforvideo";
   std::string value;
@@ -218,3 +220,5 @@ void PrintMetricsForAllStreams(const base::DictionaryValue& pc_dict) {
                                            << " is. ";
   }
 }
+
+}  // namespace test