Plumb site engagement to the renderer process.

chrome/browser/engagement/site_engagement_service.h

Index: chrome/browser/engagement/site_engagement_service.h
diff --git a/chrome/browser/engagement/site_engagement_service.h b/chrome/browser/engagement/site_engagement_service.h
index 350d30a934855a90f559122d691434087003c1fa..cb1d47ba7f877d253888d564c6b0893bb84f5731 100644
--- a/chrome/browser/engagement/site_engagement_service.h
+++ b/chrome/browser/engagement/site_engagement_service.h
@@ -19,6 +19,7 @@
 #include "chrome/browser/engagement/site_engagement_observer.h"
 #include "components/history/core/browser/history_service_observer.h"
 #include "components/keyed_service/core/keyed_service.h"
+#include "third_party/WebKit/public/platform/site_engagement.mojom.h"
 #include "ui/base/page_transition_types.h"
 
 namespace base {
@@ -75,14 +76,6 @@ class SiteEngagementService : public KeyedService,
   // the service of them.
   class Helper;
 
-  enum EngagementLevel {
-    ENGAGEMENT_LEVEL_NONE,
-    ENGAGEMENT_LEVEL_LOW,
-    ENGAGEMENT_LEVEL_MEDIUM,
-    ENGAGEMENT_LEVEL_HIGH,
-    ENGAGEMENT_LEVEL_MAX,
-  };
-
   // The name of the site engagement variation field trial.
   static const char kEngagementParams[];
 
@@ -113,7 +106,7 @@ class SiteEngagementService : public KeyedService,
   ~SiteEngagementService() override;
 
   // Returns the engagement level of |url|.
-  EngagementLevel GetEngagementLevel(const GURL& url) const;
+  blink::mojom::EngagementLevel GetEngagementLevel(const GURL& url) const;
 
   // Returns a map of all stored origins and their engagement scores.
   std::map<GURL, double> GetScoreMap() const;
@@ -124,7 +117,8 @@ class SiteEngagementService : public KeyedService,
   bool IsBootstrapped() const;
 
   // Returns whether |url| has at least the given |level| of engagement.
-  bool IsEngagementAtLeast(const GURL& url, EngagementLevel level) const;
+  bool IsEngagementAtLeast(const GURL& url,
+                           blink::mojom::EngagementLevel level) const;
 
   // Resets the engagement score |url| to |score|, clearing daily limits.
   void ResetScoreForURL(const GURL& url, double score);
@@ -133,6 +127,9 @@ class SiteEngagementService : public KeyedService,
   // clock_->Now().
   void SetLastShortcutLaunchTime(const GURL& url);
 
+  void HelperCreated(SiteEngagementService::Helper* helper);
+  void HelperDeleted(SiteEngagementService::Helper* helper);
+
   // Overridden from SiteEngagementScoreProvider.
   double GetScore(const GURL& url) const override;
   double GetTotalEngagementPoints() const override;
@@ -231,6 +228,11 @@ class SiteEngagementService : public KeyedService,
   void HandleUserInput(content::WebContents* web_contents,
                        SiteEngagementMetrics::EngagementType type);
 
+  // Called if |url| changes to |level| engagement, and informs every Helper of
+  // the change.
+  void SendLevelChangeToHelpers(const GURL& url,
+                                blink::mojom::EngagementLevel level);
+
   // Returns true if the last engagement increasing event seen by the site
   // engagement service was sufficiently long ago that we need to reset all
   // scores to be relative to now. This ensures that users who do not use the
@@ -277,6 +279,9 @@ class SiteEngagementService : public KeyedService,
   // upload.
   base::Time last_metrics_time_;
 
+  // All helpers currently attached to a WebContents.
+  std::set<SiteEngagementService::Helper*> helpers_;
+
   // A list of observers. When any origin registers an engagement-increasing
   // event, each observer's OnEngagementIncreased method will be called.
   base::ObserverList<SiteEngagementObserver> observer_list_;