Grant origins engagement for having interactions on their notifications.

chrome/browser/engagement/site_engagement_metrics.h

Index: chrome/browser/engagement/site_engagement_metrics.h
diff --git a/chrome/browser/engagement/site_engagement_metrics.h b/chrome/browser/engagement/site_engagement_metrics.h
index 4d09ca1c55b25a89604212d954f8211f8c26ad10..22e9f608f634e40d44415c4c51c5ce837b9666f7 100644
--- a/chrome/browser/engagement/site_engagement_metrics.h
+++ b/chrome/browser/engagement/site_engagement_metrics.h
@@ -27,6 +27,7 @@ class SiteEngagementMetrics {
     ENGAGEMENT_MEDIA_VISIBLE,
     ENGAGEMENT_WEBAPP_SHORTCUT_LAUNCH,
     ENGAGEMENT_FIRST_DAILY_ENGAGEMENT,
+    ENGAGEMENT_NOTIFICATION_INTERACTION,
     ENGAGEMENT_LAST,
   };
 
@@ -46,6 +47,8 @@ class SiteEngagementMetrics {
 
  private:
   FRIEND_TEST_ALL_PREFIXES(SiteEngagementServiceTest, CheckHistograms);
+  FRIEND_TEST_ALL_PREFIXES(SiteEngagementServiceTest,
+                           GetTotalNotificationPoints);
   FRIEND_TEST_ALL_PREFIXES(SiteEngagementServiceTest, LastShortcutLaunch);
   FRIEND_TEST_ALL_PREFIXES(SiteEngagementServiceTest, ScoreDecayHistograms);
   FRIEND_TEST_ALL_PREFIXES(SiteEngagementHelperTest,