Fix up certificate error reporting histograms

components/certificate_reporting/error_reporter.cc

 // 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.
 
 #include "components/certificate_reporting/error_reporter.h"
 
 #include <stddef.h>
 
 #include <set>
 #include <utility>
 
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
+#include "base/metrics/histogram_macros.h"
+#include "base/metrics/sparse_histogram.h"
 #include "components/certificate_reporting/encrypted_cert_logger.pb.h"
 #include "crypto/aead.h"
 #include "crypto/curve25519.h"
 #include "crypto/hkdf.h"
 #include "crypto/random.h"
 #include "net/url_request/report_sender.h"
 
 namespace certificate_reporting {
 
 namespace {
@@ skipping 67 matching lines @@
 
   encrypted_report->set_encrypted_report(ciphertext);
   encrypted_report->set_server_public_key_version(server_public_key_version);
   encrypted_report->set_client_public_key(reinterpret_cast<char*>(public_key),
                                           sizeof(public_key));
   encrypted_report->set_algorithm(
       EncryptedCertLoggerRequest::AEAD_ECDH_AES_128_CTR_HMAC_SHA256);
   return true;
 }
 
+// Records an UMA histogram of the net errors when certificate reports
+// fail to send.
+void RecordUMAOnFailure(const GURL& report_uri, int net_error) {
+  UMA_HISTOGRAM_SPARSE_SLOWLY("SSL.CertificateErrorReportFailure", -net_error);
+}
+
 }  // namespace
 
 ErrorReporter::ErrorReporter(
     net::URLRequestContext* request_context,
     const GURL& upload_url,
     net::ReportSender::CookiesPreference cookies_preference)
-    : ErrorReporter(
-          upload_url,
-          kServerPublicKey,
-          kServerPublicKeyVersion,
-          base::WrapUnique(
-              new net::ReportSender(request_context, cookies_preference))) {}
+    : ErrorReporter(upload_url,
+                    kServerPublicKey,
+                    kServerPublicKeyVersion,
+                    base::WrapUnique(new net::ReportSender(
+                        request_context,
+                        cookies_preference,
+                        base::Bind(RecordUMAOnFailure)))) {}
 
 ErrorReporter::ErrorReporter(
     const GURL& upload_url,
     const uint8_t server_public_key[/* 32 */],
     const uint32_t server_public_key_version,
     std::unique_ptr<net::ReportSender> certificate_report_sender)
     : certificate_report_sender_(std::move(certificate_report_sender)),
       upload_url_(upload_url),
       server_public_key_(server_public_key),
       server_public_key_version_(server_public_key_version) {
@@ skipping 42 matching lines @@
   aead.Init(&key);
 
   // Use an all-zero nonce because the key is random per-message.
   std::string nonce(aead.NonceLength(), 0);
 
   return aead.Open(encrypted_report.encrypted_report(), nonce, std::string(),
                    decrypted_serialized_report);
 }
 
 }  // namespace certificate_reporting