Reporting: Add histograms.

net/reporting/reporting_report.h

 // 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.
 
 #ifndef NET_REPORTING_REPORTING_REPORT_H_
 #define NET_REPORTING_REPORTING_REPORT_H_
 
 #include <memory>
 #include <string>
 
 #include "base/time/time.h"
 #include "net/base/net_export.h"
 #include "url/gurl.h"
 
 namespace base {
 class Value;
 }  // namespace base
 
 namespace net {
 
 // An undelivered report.
 struct NET_EXPORT ReportingReport {
  public:
+  // Used in histograms; please add new items at end and do not reorder.
+  enum class Outcome {
+    UNKNOWN = 0,
+    DISCARDED_NO_URL_REQUEST_CONTEXT = 1,
+    DISCARDED_NO_REPORTING_SERVICE = 2,
+    ERASED_FAILED = 3,
+    ERASED_EXPIRED = 4,
+    ERASED_EVICTED = 5,
+    ERASED_NETWORK_CHANGED = 6,
+    ERASED_BROWSING_DATA_REMOVED = 7,
+    ERASED_REPORTING_SHUT_DOWN = 8,
+    DELIVERED = 9,
+
+    MAX
+  };
+
   ReportingReport(const GURL& url,
                   const std::string& group,
                   const std::string& type,
                   std::unique_ptr<const base::Value> body,
                   base::TimeTicks queued,
                   int attempts);
   ~ReportingReport();
 
+  static void RecordReportDiscardedForNoURLRequestContext();
+  static void RecordReportDiscardedForNoReportingService();
+
+  void RecordOutcome(base::TimeTicks now);
+
   // The URL of the document that triggered the report. (Included in the
   // delivered report.)
   GURL url;
 
   // The endpoint group that should be used to deliver the report. (Not included
   // in the delivered report.)
   std::string group;
 
   // The type of the report. (Included in the delivered report.)
   std::string type;
 
   // The body of the report. (Included in the delivered report.)
   std::unique_ptr<const base::Value> body;
 
   // When the report was queued. (Included in the delivered report as an age
   // relative to the time of the delivery attempt.)
   base::TimeTicks queued;
 
   // The number of delivery attempts made so far, not including an active
   // attempt. (Not included in the delivered report.)
   int attempts = 0;
 
+  Outcome outcome;
+
  private:
+  bool recorded_outcome;
+
   DISALLOW_COPY_AND_ASSIGN(ReportingReport);
 };
 
 }  // namespace net
 
 #endif  // NET_REPORTING_REPORTING_REPORT_H_