Convert first contentful paint logging to the new UKM client API

components/ukm/ukm_service.cc

Index: components/ukm/ukm_service.cc
diff --git a/components/ukm/ukm_service.cc b/components/ukm/ukm_service.cc
index 1411e91e8fcf1fab8806c05ecfcc2b2f013358bd..6753d66c49466e57546a4addc79bc91d219a843b 100644
--- a/components/ukm/ukm_service.cc
+++ b/components/ukm/ukm_service.cc
@@ -388,7 +388,7 @@ void UkmService::UpdateSourceURL(const content::GlobalRequestID& source_id,
     if (source_id != source->id())
       continue;
 
-    source->set_committed_url(url);
+    source->set_url(url);
     return;
   }
 
@@ -398,7 +398,7 @@ void UkmService::UpdateSourceURL(const content::GlobalRequestID& source_id,
   }
   std::unique_ptr<UkmSource> source = base::MakeUnique<UkmSource>();
   source->set_id(source_id);
-  source->set_committed_url(url);
+  source->set_url(url);
   sources_.push_back(std::move(source));
 }