Reporting: Add histograms.

net/reporting/reporting_cache.cc

Index: net/reporting/reporting_cache.cc
diff --git a/net/reporting/reporting_cache.cc b/net/reporting/reporting_cache.cc
index 7920a20ca4f43552512d6693240954e61e3c969a..21a06efcaf5cf1787b2916c1a4777a68fbf257ca 100644
--- a/net/reporting/reporting_cache.cc
+++ b/net/reporting/reporting_cache.cc
@@ -48,7 +48,20 @@ ReportingCache::ReportingCache(ReportingContext* context) : context_(context) {
   DCHECK(context_);
 }
 
-ReportingCache::~ReportingCache() {}
+ReportingCache::~ReportingCache() {
+  base::TimeTicks now = tick_clock()->NowTicks();
+
+  // Mark all undoomed reports as erased at shutdown, and record outcomes of
+  // all remaining reports (doomed or not).
+  for (auto it = reports_.begin(); it != reports_.end(); ++it) {
+    ReportingReport* report = it->second.get();
+    if (!base::ContainsKey(doomed_reports_, report))
+      report->outcome = ReportingReport::Outcome::ERASED_REPORTING_SHUT_DOWN;
+    report->RecordOutcome(now);
+  }
+
+  reports_.clear();
+}
 
 void ReportingCache::AddReport(const GURL& url,
                                const std::string& group,
@@ -71,8 +84,8 @@ void ReportingCache::AddReport(const GURL& url,
     // The newly-added report isn't pending, so even if all other reports are
     // pending, the cache should have a report to evict.
     DCHECK(!base::ContainsKey(pending_reports_, to_evict));
-    size_t erased = reports_.erase(to_evict);
-    DCHECK_EQ(1u, erased);
+    reports_[to_evict]->outcome = ReportingReport::Outcome::ERASED_EVICTED;
+    RemoveReportInternal(to_evict);
   }
 
   context_->NotifyCacheUpdated();
@@ -108,7 +121,8 @@ void ReportingCache::ClearReportsPending(
     }
   }
 
-  RemoveReports(reports_to_remove);
+  for (const ReportingReport* report : reports_to_remove)
+    RemoveReportInternal(report);
 }
 
 void ReportingCache::IncrementReportsAttempts(
@@ -122,34 +136,34 @@ void ReportingCache::IncrementReportsAttempts(
 }
 
 void ReportingCache::RemoveReports(
-    const std::vector<const ReportingReport*>& reports) {
+    const std::vector<const ReportingReport*>& reports,
+    ReportingReport::Outcome outcome) {
   for (const ReportingReport* report : reports) {
+    reports_[report]->outcome = outcome;
     if (base::ContainsKey(pending_reports_, report)) {
       doomed_reports_.insert(report);
     } else {
       DCHECK(!base::ContainsKey(doomed_reports_, report));
-      size_t erased = reports_.erase(report);
-      DCHECK_EQ(1u, erased);
+      RemoveReportInternal(report);
     }
   }
 
   context_->NotifyCacheUpdated();
 }
 
-void ReportingCache::RemoveAllReports() {
-  std::vector<std::unordered_map<const ReportingReport*,
-                                 std::unique_ptr<ReportingReport>>::iterator>
-      reports_to_remove;
+void ReportingCache::RemoveAllReports(ReportingReport::Outcome outcome) {
+  std::vector<const ReportingReport*> reports_to_remove;
   for (auto it = reports_.begin(); it != reports_.end(); ++it) {
     ReportingReport* report = it->second.get();
+    report->outcome = outcome;
     if (!base::ContainsKey(pending_reports_, report))
-      reports_to_remove.push_back(it);
+      reports_to_remove.push_back(report);
     else
       doomed_reports_.insert(report);
   }
 
-  for (auto& it : reports_to_remove)
-    reports_.erase(it);
+  for (const ReportingReport* report : reports_to_remove)
+    RemoveReportInternal(report);
 
   context_->NotifyCacheUpdated();
 }
@@ -268,6 +282,12 @@ void ReportingCache::RemoveAllClients() {
   context_->NotifyCacheUpdated();
 }
 
+void ReportingCache::RemoveReportInternal(const ReportingReport* report) {
+  reports_[report]->RecordOutcome(tick_clock()->NowTicks());
+  size_t erased = reports_.erase(report);
+  DCHECK_EQ(1u, erased);
+}
+
 const ReportingReport* ReportingCache::FindReportToEvict() const {
   const ReportingReport* earliest_queued = nullptr;