Reporting: Add histograms.

net/reporting/reporting_network_change_observer.cc

 // Copyright 2017 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.
 
 #include "net/reporting/reporting_network_change_observer.h"
 
 #include "base/macros.h"
 #include "net/base/network_change_notifier.h"
 #include "net/reporting/reporting_cache.h"
 #include "net/reporting/reporting_context.h"
 #include "net/reporting/reporting_policy.h"
+#include "net/reporting/reporting_report.h"
 
 namespace net {
 
 namespace {
 
 class ReportingNetworkChangeObserverImpl
     : public ReportingNetworkChangeObserver,
       public NetworkChangeNotifier::NetworkChangeObserver {
  public:
   ReportingNetworkChangeObserverImpl(ReportingContext* context)
       : context_(context) {
     NetworkChangeNotifier::AddNetworkChangeObserver(this);
   }
 
   // ReportingNetworkChangeObserver implementation:
   ~ReportingNetworkChangeObserverImpl() override {
     NetworkChangeNotifier::RemoveNetworkChangeObserver(this);
   }
 
   // NetworkChangeNotifier::NetworkChangeObserver implementation:
   void OnNetworkChanged(NetworkChangeNotifier::ConnectionType type) override {
     // Every network change will be preceded by a call with CONNECTION_NONE, and
     // NetworkChangeNotifier suggests that destructive actions be performed in
     // the call with CONNECTION_NONE, so clear reports and/or clients only in
     // that case.
     if (type != NetworkChangeNotifier::ConnectionType::CONNECTION_NONE)
       return;
 
     if (context_->policy().clear_reports_on_network_changes)
-      context_->cache()->RemoveAllReports();
+      context_->cache()->RemoveAllReports(
+          ReportingReport::Outcome::ERASED_NETWORK_CHANGED);
 
     if (context_->policy().clear_clients_on_network_changes)
       context_->cache()->RemoveAllClients();
   }
 
  private:
   ReportingContext* context_;
 
   DISALLOW_COPY_AND_ASSIGN(ReportingNetworkChangeObserverImpl);
 };
 
 }  // namespace
 
 // static
 std::unique_ptr<ReportingNetworkChangeObserver>
 ReportingNetworkChangeObserver::Create(ReportingContext* context) {
   return base::MakeUnique<ReportingNetworkChangeObserverImpl>(context);
 }
 
 ReportingNetworkChangeObserver::~ReportingNetworkChangeObserver() {}
 
 }  // namespace net