Log an immediate variant of FirstContentfulPaint.

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 fdcefd58ab7bf4310675dceaaf64c82301896113..91e3384164bc18815e0c63d519143906946971df 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
@@ -132,6 +132,16 @@ TEST_F(CorePageLoadMetricsObserverTest, MultipleMetricsAfterCommits) {
   NavigateAndCommit(GURL(kDefaultTestUrl));
   SimulateTimingUpdate(timing);
 
+  // Verify that the non-immediate FCP has not yet been logged, but the
+  // immediate FCP is logged before the next navigation.
+  histogram_tester().ExpectTotalCount(internal::kHistogramFirstContentfulPaint,
+                                      0);
+  histogram_tester().ExpectTotalCount(
+      internal::kHistogramFirstContentfulPaintImmediate, 1);
+  histogram_tester().ExpectBucketCount(
+      internal::kHistogramFirstContentfulPaintImmediate,
+      first_contentful_paint.InMilliseconds(), 1);
+
   NavigateAndCommit(GURL(kDefaultTestUrl2));
 
   page_load_metrics::PageLoadTiming timing2;
@@ -157,6 +167,17 @@ TEST_F(CorePageLoadMetricsObserverTest, MultipleMetricsAfterCommits) {
       internal::kHistogramDomLoadingToDomContentLoaded,
       (dom_content - dom_loading).InMilliseconds(), 1);
 
+  histogram_tester().ExpectTotalCount(internal::kHistogramFirstContentfulPaint,
+                                      1);
+  histogram_tester().ExpectBucketCount(internal::kHistogramFirstContentfulPaint,
+                                       first_contentful_paint.InMilliseconds(),
+                                       1);
+
+  // Verify that no additional immediate metrics were logged as a result of
+  // navigation.
+  histogram_tester().ExpectTotalCount(
+      internal::kHistogramFirstContentfulPaintImmediate, 1);
+
   histogram_tester().ExpectTotalCount(
       internal::kHistogramDomLoadingToFirstContentfulPaint, 1);
   histogram_tester().ExpectBucketCount(