[page_load_metrics] Add a NavigationThrottle for richer abort metrics

chrome/browser/page_load_metrics/observers/from_gws_page_load_metrics_observer_unittest.cc

Index: chrome/browser/page_load_metrics/observers/from_gws_page_load_metrics_observer_unittest.cc
diff --git a/chrome/browser/page_load_metrics/observers/from_gws_page_load_metrics_observer_unittest.cc b/chrome/browser/page_load_metrics/observers/from_gws_page_load_metrics_observer_unittest.cc
index 2c14f944c1617f24043e3b96b2f3b55cc47c8755..97289454be8014db5a47aaa02e754ad8ebd98c25 100644
--- a/chrome/browser/page_load_metrics/observers/from_gws_page_load_metrics_observer_unittest.cc
+++ b/chrome/browser/page_load_metrics/observers/from_gws_page_load_metrics_observer_unittest.cc
@@ -443,14 +443,14 @@ TEST_F(FromGWSPageLoadMetricsObserverTest,
   }
 }
 
-TEST_F(FromGWSPageLoadMetricsObserverTest, UnknownNavigationBeforeCommit) {
+TEST_F(FromGWSPageLoadMetricsObserverTest, NewNavigationBeforeCommit) {
   NavigateAndCommit(GURL(kGoogleSearchResultsUrl));
   StartNavigation(GURL("http://example.test"));
 
   // Simulate the user performing another navigation before commit.
-  StartNavigation(GURL("https://www.example.com"));
+  NavigateAndCommit(GURL("https://www.example.com"));
   histogram_tester().ExpectTotalCount(
-      internal::kHistogramFromGWSAbortUnknownNavigationBeforeCommit, 1);
+      internal::kHistogramFromGWSAbortNewNavigationBeforeCommit, 1);
 }
 
 TEST_F(FromGWSPageLoadMetricsObserverTest, NewNavigationBeforePaint) {