Implement a site engagement score based on time-on-site.

chrome/browser/engagement/site_engagement_eviction_policy_unittest.cc

Index: chrome/browser/engagement/site_engagement_eviction_policy_unittest.cc
diff --git a/chrome/browser/engagement/site_engagement_eviction_policy_unittest.cc b/chrome/browser/engagement/site_engagement_eviction_policy_unittest.cc
index 49757f2b67911c57eac4425e70bc17e4c0c25fe6..733c5aa6d3b02725439a3b1017cf3ef5809d1e99 100644
--- a/chrome/browser/engagement/site_engagement_eviction_policy_unittest.cc
+++ b/chrome/browser/engagement/site_engagement_eviction_policy_unittest.cc
@@ -19,21 +19,23 @@ class TestSiteEngagementScoreProvider : public SiteEngagementScoreProvider {
 
   virtual ~TestSiteEngagementScoreProvider() {}
 
-  int GetScore(const GURL& url) override { return engagement_score_map_[url]; }
+  double GetScore(const GURL& url) override {
+    return engagement_score_map_[url];
+  }
 
-  int GetTotalEngagementPoints() override {
-    int total = 0;
+  double GetTotalEngagementPoints() override {
+    double total = 0;
     for (const auto& site : engagement_score_map_)
       total += site.second;
     return total;
   }
 
-  void SetScore(const GURL& origin, int score) {
+  void SetScore(const GURL& origin, double score) {
     engagement_score_map_[origin] = score;
   }
 
  private:
-  std::map<GURL, int> engagement_score_map_;
+  std::map<GURL, double> engagement_score_map_;
 
   DISALLOW_COPY_AND_ASSIGN(TestSiteEngagementScoreProvider);
 };