SiteEngagementService: De-duplicate logic to notify observers.

Change-Id: Ic11c98558f29eeafc05b2bf3a082c808f5ace023
Reviewed-on: https://chromium-review.googlesource.com/792831Reviewed-by: Dominick Ng <dominickn@chromium.org>
Commit-Queue: Matt Giuca <mgiuca@chromium.org>
Cr-Commit-Position: refs/heads/master@{#519586}

chrome/browser/engagement/site_engagement_service.cc

@@ -185,9 +185,7 @@ void SiteEngagementService::HandleNotificationInteraction(const GURL& url) {
   AddPoints(url, SiteEngagementScore::GetNotificationInteractionPoints());
 
   RecordMetrics();
-  double score = GetScore(url);
-  for (SiteEngagementObserver& observer : observer_list_)
-    observer.OnEngagementIncreased(nullptr /* web_contents */, url, score);
+  OnEngagementIncreased(nullptr /* web_contents */, url);
 }
 
 bool SiteEngagementService::IsBootstrapped() const {
@@ -515,9 +513,7 @@ void SiteEngagementService::HandleMediaPlaying(
                            : SiteEngagementScore::GetVisibleMediaPoints());
 
   RecordMetrics();
-  double score = GetScore(url);
-  for (SiteEngagementObserver& observer : observer_list_)
-    observer.OnEngagementIncreased(web_contents, url, score);
+  OnEngagementIncreased(web_contents, url);
 }
 
 void SiteEngagementService::HandleNavigation(content::WebContents* web_contents,
@@ -531,9 +527,7 @@ void SiteEngagementService::HandleNavigation(content::WebContents* web_contents,
   AddPoints(url, SiteEngagementScore::GetNavigationPoints());
 
   RecordMetrics();
-  double score = GetScore(url);
-  for (SiteEngagementObserver& observer : observer_list_)
-    observer.OnEngagementIncreased(web_contents, url, score);
+  OnEngagementIncreased(web_contents, url);
 }
 
 void SiteEngagementService::HandleUserInput(
@@ -547,6 +541,12 @@ void SiteEngagementService::HandleUserInput(
   AddPoints(url, SiteEngagementScore::GetUserInputPoints());
 
   RecordMetrics();
+  OnEngagementIncreased(web_contents, url);
+}
+
+void SiteEngagementService::OnEngagementIncreased(
+    content::WebContents* web_contents,
+    const GURL& url) {
   double score = GetScore(url);
   for (SiteEngagementObserver& observer : observer_list_)
     observer.OnEngagementIncreased(web_contents, url, score);

chrome/browser/engagement/site_engagement_service.h

@@ -254,6 +254,13 @@ class SiteEngagementService : public KeyedService,
   void HandleUserInput(content::WebContents* web_contents,
                        SiteEngagementMetrics::EngagementType type);
 
+  // Called when the engagement for |url| loaded in |web_contents| increases.
+  // Calls OnEngagementIncreased in all observers. |web_contents| may be null if
+  // the engagement has increased when |url| is not in a tab, e.g. from a
+  // notification interaction.
+  void OnEngagementIncreased(content::WebContents* web_contents,
+                             const GURL& url);
+
   // Called if |url| changes to |level| engagement, and informs every Helper of
   // the change.
   void SendLevelChangeToHelpers(const GURL& url,