Add network quality change events to net log

net/nqe/network_quality_estimator.h

Index: net/nqe/network_quality_estimator.h
diff --git a/net/nqe/network_quality_estimator.h b/net/nqe/network_quality_estimator.h
index e4a9d97471a3e487e4987df663d54f3375c8960f..457367491fdabc5e8b3bbfe4b87def35402c44cd 100644
--- a/net/nqe/network_quality_estimator.h
+++ b/net/nqe/network_quality_estimator.h
@@ -21,6 +21,7 @@
 #include "base/time/time.h"
 #include "net/base/net_export.h"
 #include "net/base/network_change_notifier.h"
+#include "net/log/net_log_with_source.h"
 #include "net/nqe/cached_network_quality.h"
 #include "net/nqe/effective_connection_type.h"
 #include "net/nqe/external_estimate_provider.h"
@@ -38,6 +39,8 @@ class TickClock;
 
 namespace net {
 
+class NetLog;
+
 namespace nqe {
 namespace internal {
 class ThroughputAnalyzer;
@@ -176,10 +179,12 @@ class NET_EXPORT NetworkQualityEstimator
   // Creates a new NetworkQualityEstimator.
   // |variation_params| is the map containing all field trial parameters
   // related to NetworkQualityEstimator field trial.
-  // |external_estimates_provider| may be NULL.
+  // |external_estimates_provider| may be NULL. The caller must guarantee that
+  // |net_log| outlives |this|.
   NetworkQualityEstimator(
       std::unique_ptr<ExternalEstimateProvider> external_estimates_provider,
-      const std::map<std::string, std::string>& variation_params);
+      const std::map<std::string, std::string>& variation_params,
+      NetLog* net_log);
 
   // Construct a NetworkQualityEstimator instance allowing for test
   // configuration. Registers for network type change notifications so estimates
@@ -192,12 +197,14 @@ class NET_EXPORT NetworkQualityEstimator
   // used for network quality estimation.
   // |use_smaller_responses_for_tests| should only be true when testing.
   // Allows the responses smaller than |kMinTransferSizeInBits| to be used for
-  // network quality estimation.
+  // network quality estimation. The caller must guarantee that |net_log|
+  // outlives |this|.
   NetworkQualityEstimator(
       std::unique_ptr<ExternalEstimateProvider> external_estimates_provider,
       const std::map<std::string, std::string>& variation_params,
       bool use_local_host_requests_for_tests,
-      bool use_smaller_responses_for_tests);
+      bool use_smaller_responses_for_tests,
+      NetLog* net_log);
 
   ~NetworkQualityEstimator() override;
 
@@ -310,7 +317,8 @@ class NET_EXPORT NetworkQualityEstimator
       const std::map<std::string, std::string>& variation_params,
       bool use_local_host_requests_for_tests,
       bool use_smaller_responses_for_tests,
-      bool add_default_platform_observations);
+      bool add_default_platform_observations,
+      const NetLogWithSource& net_log);
 
   // NetworkChangeNotifier::ConnectionTypeObserver implementation:
   void OnConnectionTypeChanged(
@@ -755,6 +763,8 @@ class NET_EXPORT NetworkQualityEstimator
 
   base::ThreadChecker thread_checker_;
 
+  NetLogWithSource net_log_;
+
   base::WeakPtrFactory<NetworkQualityEstimator> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(NetworkQualityEstimator);