Measure packet loss so we can use it to select ICE candidate pairs.

webrtc/p2p/BUILD.gn

Index: webrtc/p2p/BUILD.gn
diff --git a/webrtc/p2p/BUILD.gn b/webrtc/p2p/BUILD.gn
index 07fcdf44f83f0a4d317e4bd2c5b838a60adc36bd..b45865359f40f1a5a66a2b11979eeb3c074e6954 100644
--- a/webrtc/p2p/BUILD.gn
+++ b/webrtc/p2p/BUILD.gn
@@ -37,6 +37,8 @@ rtc_static_library("rtc_p2p") {
     "base/p2pconstants.h",
     "base/p2ptransportchannel.cc",
     "base/p2ptransportchannel.h",
+    "base/packetlossestimator.cc",
+    "base/packetlossestimator.h",
     "base/packetsocketfactory.h",
     "base/packettransportinterface.h",
     "base/packettransportinternal.h",
@@ -153,6 +155,7 @@ if (rtc_include_tests) {
       "base/jseptransport_unittest.cc",
       "base/mockicetransport.h",
       "base/p2ptransportchannel_unittest.cc",
+      "base/packetlossestimator_unittest.cc",
       "base/port_unittest.cc",
       "base/portallocator_unittest.cc",
       "base/pseudotcp_unittest.cc",