NQE: Add net log events when there is a significant change in metrics

net/nqe/network_quality_estimator.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef NET_NQE_NETWORK_QUALITY_ESTIMATOR_H_
 #define NET_NQE_NETWORK_QUALITY_ESTIMATOR_H_
 
 #include <stdint.h>
 
 #include <map>
 #include <memory>
 #include <string>
 
 #include "base/compiler_specific.h"
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
 #include "base/threading/thread_checker.h"
 #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/event_creator.h"
 #include "net/nqe/external_estimate_provider.h"
 #include "net/nqe/network_id.h"
 #include "net/nqe/network_quality.h"
 #include "net/nqe/network_quality_observation.h"
 #include "net/nqe/network_quality_observation_source.h"
 #include "net/nqe/network_quality_store.h"
 #include "net/nqe/observation_buffer.h"
 #include "net/socket/socket_performance_watcher_factory.h"
 
 namespace base {
@@ skipping 719 matching lines @@
   std::unique_ptr<nqe::internal::NetworkQualityStore> network_quality_store_;
 
   // True if effective connection type value has been forced via variation
   // parameters. If set to true, GetEffectiveConnectionType() will always return
   // |forced_effective_connection_type_|.
   const bool forced_effective_connection_type_set_;
   const EffectiveConnectionType forced_effective_connection_type_;
 
   base::ThreadChecker thread_checker_;
 
-  NetLogWithSource net_log_;
+  // Manages the writing of events to the net log.
+  nqe::internal::EventCreator event_creator_;
 
   base::WeakPtrFactory<NetworkQualityEstimator> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(NetworkQualityEstimator);
 };
 
 }  // namespace net
 
 #endif  // NET_NQE_NETWORK_QUALITY_ESTIMATOR_H_