[PageLoadMetrics] Record bytes usage per page

chrome/browser/page_load_metrics/observers/core_page_load_metrics_observer_unittest.cc

Index: chrome/browser/page_load_metrics/observers/core_page_load_metrics_observer_unittest.cc
diff --git a/chrome/browser/page_load_metrics/observers/core_page_load_metrics_observer_unittest.cc b/chrome/browser/page_load_metrics/observers/core_page_load_metrics_observer_unittest.cc
index 773e54abacff0a5b8935428472c013472073dfae..75d7ab6d4a509391c59ce37599f96ec98632ecc2 100644
--- a/chrome/browser/page_load_metrics/observers/core_page_load_metrics_observer_unittest.cc
+++ b/chrome/browser/page_load_metrics/observers/core_page_load_metrics_observer_unittest.cc
@@ -481,6 +481,17 @@ TEST_F(CorePageLoadMetricsObserverTest, NewNavigation) {
       timing.parse_start.value().InMilliseconds(), 1);
 }
 
+TEST_F(CorePageLoadMetricsObserverTest, BytesCounted) {
+  NavigateAndCommit(GURL(kDefaultTestUrl));
+  NavigateAndCommit(GURL(kDefaultTestUrl2));
+  histogram_tester().ExpectTotalCount(internal::kHistogramTotalBytesOnComplete,
+                                      1);
+  histogram_tester().ExpectTotalCount(
+      internal::kHistogramNetworkBytesOnComplete, 1);
+  histogram_tester().ExpectTotalCount(internal::kHistogramCacheBytesOnComplete,
+                                      1);
+}
+
 TEST_F(CorePageLoadMetricsObserverTest, FirstMeaningfulPaint) {
   page_load_metrics::PageLoadTiming timing;
   timing.navigation_start = base::Time::FromDoubleT(1);