Add support for logging additional metrics in UKM.

components/ukm/ukm_source.cc

Index: components/ukm/ukm_source.cc
diff --git a/components/ukm/ukm_source.cc b/components/ukm/ukm_source.cc
index dc2f9e033a4f84435e34b0adf0892b661c9a01d9..d0c51f97a6199cfc7d3b4c7d97f3f3c917c64475 100644
--- a/components/ukm/ukm_source.cc
+++ b/components/ukm/ukm_source.cc
@@ -12,10 +12,21 @@ UkmSource::UkmSource() = default;
 UkmSource::~UkmSource() = default;
 
 void UkmSource::PopulateProto(Source* proto_source) {
-  proto_source->set_url(committed_url_.spec());
+  proto_source->set_url(url_.spec());
 
-  proto_source->set_first_contentful_paint_msec(
-      first_contentful_paint_.InMilliseconds());
+  if (parse_start_)
+    proto_source->set_parse_start_msec(parse_start_.value().InMilliseconds());
+  if (total_time_)
+    proto_source->set_total_time_msec(total_time_.value().InMilliseconds());
+
+  if (first_contentful_paint_) {
+    proto_source->set_first_contentful_paint_msec(
+        first_contentful_paint_.value().InMilliseconds());
+  }
+  if (first_meaningful_paint_) {
+    proto_source->set_experimental_first_meaningful_paint_msec(
+        first_meaningful_paint_.value().InMilliseconds());
+  }
 }
 
 }  // namespace ukm