PeerConnection[Interface]::GetStats(RTCStatsCollectorCallback*) added.

webrtc/api/BUILD.gn

Index: webrtc/api/BUILD.gn
diff --git a/webrtc/api/BUILD.gn b/webrtc/api/BUILD.gn
index 4f15bc4b05f872c59aece2224fb599ebad192180..b7cd679f28d2427fdbf959db0631739a9b753642 100644
--- a/webrtc/api/BUILD.gn
+++ b/webrtc/api/BUILD.gn
@@ -84,9 +84,8 @@ rtc_source_set("libjingle_peerconnection") {
     "proxy.h",
     "remoteaudiosource.cc",
     "remoteaudiosource.h",
-    "rtcstats.h",
-    "rtcstats_objects.h",
-    "rtcstatsreport.h",
+    "rtcstatscollector.cc",
+    "rtcstatscollector.h",
     "rtpparameters.h",
     "rtpreceiver.cc",
     "rtpreceiver.h",
@@ -125,9 +124,11 @@ rtc_source_set("libjingle_peerconnection") {
 
   deps = [
     ":call_api",
+    ":rtc_stats_api",
     "../call",
     "../media",
     "../pc",
+    "../stats",
   ]
 
   if (rtc_use_quic) {
@@ -298,6 +299,20 @@ if (is_android && !build_with_chromium) {
   }
 }
 
+# GYP version: webrtc/api/api.gyp:rtc_stats_api
+rtc_source_set("rtc_stats_api") {
+  cflags = []
+  sources = [
+    "stats/rtcstats.h",
+    "stats/rtcstats_objects.h",
+    "stats/rtcstatsreport.h",
+  ]
+
+  deps = [
+    "../base:rtc_base_approved",
+  ]
+}
+
 if (rtc_include_tests) {
   config("peerconnection_unittests_config") {
     # The warnings below are enabled by default. Since GN orders compiler flags
@@ -336,6 +351,7 @@ if (rtc_include_tests) {
       "peerconnectionfactory_unittest.cc",
       "peerconnectioninterface_unittest.cc",
       "proxy_unittest.cc",
+      "rtcstatscollector_unittest.cc",
       "rtpsenderreceiver_unittest.cc",
       "statscollector_unittest.cc",
       "test/fakeaudiocapturemodule.cc",