Revert of Trace the stats report as JSON instead of each stat separately.

webrtc/pc/rtcstatscollector.cc

Index: webrtc/pc/rtcstatscollector.cc
diff --git a/webrtc/pc/rtcstatscollector.cc b/webrtc/pc/rtcstatscollector.cc
index 56ea3c5eaf417b1e4c8fce6c493e09a372f90472..4952012648c5f22a1dc37d50c3adf129756efa6b 100644
--- a/webrtc/pc/rtcstatscollector.cc
+++ b/webrtc/pc/rtcstatscollector.cc
@@ -31,6 +31,18 @@
 namespace webrtc {
 
 namespace {
+
+const int kStatTypeMemberNameAndIdMaxLen = 1024;
+
+std::string GetStatTypeMemberNameAndId(const RTCStats& stats,
+                                       const RTCStatsMemberInterface* member) {
+  RTC_DCHECK(strlen(stats.type()) + strlen(member->name())
+             + stats.id().size() + 3 < kStatTypeMemberNameAndIdMaxLen);
+  char buffer[kStatTypeMemberNameAndIdMaxLen];
+  rtc::sprintfn(&buffer[0], sizeof(buffer), "%s.%s.%s", stats.type(),
+                member->name(), stats.id().c_str());
+  return buffer;
+}
 
 std::string RTCCertificateIDFromFingerprint(const std::string& fingerprint) {
   return "RTCCertificate_" + fingerprint;
@@ -763,8 +775,16 @@
     // Trace WebRTC Stats when getStats is called on Javascript.
     // This allows access to WebRTC stats from trace logs. To enable them,
     // select the "webrtc_stats" category when recording traces.
-    TRACE_EVENT_INSTANT1("webrtc_stats", "webrtc_stats", "report",
-                         cached_report_->ToJson());
+    for (const RTCStats& stats : *cached_report_) {
+      for (const RTCStatsMemberInterface* member : stats.Members()) {
+        if (member->is_defined()) {
+          TRACE_EVENT_INSTANT2("webrtc_stats", "webrtc_stats",
+                               "value", member->ValueToString(),
+                               "type.name.id", GetStatTypeMemberNameAndId(
+                                   stats, member));
+        }
+      }
+    }
     DeliverCachedReport();
   }
 }