Bucket FirstContentfulPaint timing into High/Low res clock buckets

components/page_load_metrics/browser/metrics_web_contents_observer.cc

Index: components/page_load_metrics/browser/metrics_web_contents_observer.cc
diff --git a/components/page_load_metrics/browser/metrics_web_contents_observer.cc b/components/page_load_metrics/browser/metrics_web_contents_observer.cc
index c112a7141646455f8da79402c6fdd9cd2bd1b8ec..b9850ec0cfb32bf330b82dd9a5ac0278b4303f24 100644
--- a/components/page_load_metrics/browser/metrics_web_contents_observer.cc
+++ b/components/page_load_metrics/browser/metrics_web_contents_observer.cc
@@ -279,6 +279,15 @@ void PageLoadTracker::RecordTimingHistograms() {
     if (first_contentful_paint < background_delta) {
       PAGE_LOAD_HISTOGRAM(kHistogramFirstContentfulPaint,
                           first_contentful_paint);
+      // Bucket these histograms into high/low resolution clock systems. This
+      // might point us to directions that will de-noise some UMA.
+      if (base::TimeTicks::IsHighResolution()) {
+        PAGE_LOAD_HISTOGRAM(kHistogramFirstContentfulPaintHigh,
+                            first_contentful_paint);
+      } else {
+        PAGE_LOAD_HISTOGRAM(kHistogramFirstContentfulPaintLow,
+                            first_contentful_paint);
+      }
     } else {
       PAGE_LOAD_HISTOGRAM(kBackgroundHistogramFirstContentfulPaint,
                           first_contentful_paint);