Expose packet loss counts from QUIC to NetworkQualityEstimator

net/base/socket_performance_watcher_factory.h

Index: net/base/socket_performance_watcher_factory.h
diff --git a/net/base/socket_performance_watcher_factory.h b/net/base/socket_performance_watcher_factory.h
index cbd607ab3366cbba1e24dea1a6dcaab205dd8320..db8e007914f798b3834e9186d26ae127ff456329 100644
--- a/net/base/socket_performance_watcher_factory.h
+++ b/net/base/socket_performance_watcher_factory.h
@@ -5,6 +5,8 @@
 #ifndef NET_BASE_SOCKET_PERFORMANCE_WATCHER_FACTORY_H_
 #define NET_BASE_SOCKET_PERFORMANCE_WATCHER_FACTORY_H_
 
+#include <stdint.h>
+
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
 #include "net/base/net_export.h"
@@ -42,6 +44,20 @@ class NET_EXPORT_PRIVATE SocketPerformanceWatcherFactory {
   virtual void OnUpdatedRTTAvailable(const Protocol protocol,
                                      const base::TimeDelta& rtt) = 0;
 
+  // Called when updated packet count at transport layer is available.
+  // |protocol| is the protocol that was used by the watcher.
+  // |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.
+  virtual void OnUpdatedPacketCountAvailable(
+      Protocol protocol,
+      uint64_t num_packets_lost,
+      uint64_t num_packets_received_in_order,
+      uint64_t num_packets_received_not_in_order) = 0;
+
  protected:
   SocketPerformanceWatcherFactory() {}