Expose packet loss counts from QUIC to NetworkQualityEstimator

net/base/socket_performance_watcher.h

Index: net/base/socket_performance_watcher.h
diff --git a/net/base/socket_performance_watcher.h b/net/base/socket_performance_watcher.h
index e0e76327ce63541e8d0dc2ba23215d34f953df41..3a7894612bcf3cd042823e8f77b4cdafcdb7362a 100644
--- a/net/base/socket_performance_watcher.h
+++ b/net/base/socket_performance_watcher.h
@@ -5,6 +5,8 @@
 #ifndef NET_BASE_SOCKET_PERFORMANCE_WATCHER_H_
 #define NET_BASE_SOCKET_PERFORMANCE_WATCHER_H_
 
+#include <stdint.h>
+
 #include "base/macros.h"
 #include "net/base/net_export.h"
 #include "net/base/socket_performance_watcher_factory.h"
@@ -33,6 +35,18 @@ class NET_EXPORT_PRIVATE SocketPerformanceWatcher {
   // made, hence no timestamp.
   void OnUpdatedRTTAvailable(const base::TimeDelta& rtt) const;
 
+  // Called when an updated packet count at the transport layer is available.
+  // |num_packets_lost| is the number of packets lost.
+  // |num_packets_received_in_order| is the number of packets received in
+  // order. |num_packets_received_not_in_order| is the number of packets
+  // received out of order. All the counts are since the last call to the
+  // OnUpdatedPacketCountAvailable. This method is called immediately after the
+  // observation is made, hence no timestamp.
+  void OnUpdatedPacketCountAvailable(
+      uint64_t num_packets_lost,
+      uint64_t num_packets_received_in_order,
+      uint64_t num_packets_received_not_in_order) const;
+
  private:
   // Transport layer protocol used by the socket that |this| is watching.
   const SocketPerformanceWatcherFactory::Protocol protocol_;