Add ServiceWorker.NavigationPreload.HeaderSize UMA

content/browser/service_worker/service_worker_metrics.cc

 // Copyright 2014 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 "content/browser/service_worker/service_worker_metrics.h"
 
 #include <limits>
 #include <string>
 
 #include "base/metrics/histogram_macros.h"
@@ skipping 743 matching lines @@
                               status, SERVICE_WORKER_ERROR_MAX_VALUE);
   } else if (failure_count == 2) {
     UMA_HISTOGRAM_ENUMERATION("ServiceWorker.StartWorker.AfterFailureStreak_2",
                               status, SERVICE_WORKER_ERROR_MAX_VALUE);
   } else if (failure_count == 3) {
     UMA_HISTOGRAM_ENUMERATION("ServiceWorker.StartWorker.AfterFailureStreak_3",
                               status, SERVICE_WORKER_ERROR_MAX_VALUE);
   }
 }
 
+void ServiceWorkerMetrics::RecordNavigationPreloadRequestHeaderSize(
+    size_t size) {
+  UMA_HISTOGRAM_COUNTS_100000("ServiceWorker.NavigationPreload.HeaderSize",
+                              size);
+}
+
 }  // namespace content