Plumb site engagement to the renderer process.

chrome/browser/engagement/site_engagement_service.cc

Index: chrome/browser/engagement/site_engagement_service.cc
diff --git a/chrome/browser/engagement/site_engagement_service.cc b/chrome/browser/engagement/site_engagement_service.cc
index 66a2b4976dcf901a748a3c385fe9a88499480e08..e089262e14b83e60df7a544e59ae69849fae1d89 100644
--- a/chrome/browser/engagement/site_engagement_service.cc
+++ b/chrome/browser/engagement/site_engagement_service.cc
@@ -21,6 +21,7 @@
 #include "chrome/browser/banners/app_banner_settings_helper.h"
 #include "chrome/browser/content_settings/host_content_settings_map_factory.h"
 #include "chrome/browser/engagement/site_engagement_eviction_policy.h"
+#include "chrome/browser/engagement/site_engagement_helper.h"
 #include "chrome/browser/engagement/site_engagement_metrics.h"
 #include "chrome/browser/engagement/site_engagement_score.h"
 #include "chrome/browser/engagement/site_engagement_service_factory.h"
@@ -33,7 +34,9 @@
 #include "components/history/core/browser/history_service.h"
 #include "components/prefs/pref_service.h"
 #include "content/public/browser/browser_thread.h"
+#include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/web_contents.h"
+#include "content/public/common/associated_interface_provider.h"
 #include "url/gurl.h"
 
 namespace {
@@ -123,24 +126,12 @@ SiteEngagementService::~SiteEngagementService() {
     history->RemoveObserver(this);
 }
 
-SiteEngagementService::EngagementLevel
+blink::mojom::EngagementLevel
 SiteEngagementService::GetEngagementLevel(const GURL& url) const {
-  DCHECK_LT(SiteEngagementScore::GetMediumEngagementBoundary(),
-            SiteEngagementScore::GetHighEngagementBoundary());
-  double score = GetScore(url);
-  if (score == 0)
-    return ENGAGEMENT_LEVEL_NONE;
-
-  if (score < SiteEngagementScore::GetMediumEngagementBoundary())
-    return ENGAGEMENT_LEVEL_LOW;
-
-  if (score < SiteEngagementScore::GetHighEngagementBoundary())
-    return ENGAGEMENT_LEVEL_MEDIUM;
-
-  if (score < SiteEngagementScore::kMaxPoints)
-    return ENGAGEMENT_LEVEL_HIGH;
+  if (IsLastEngagementStale())
+    CleanupEngagementScores(true);
 
-  return ENGAGEMENT_LEVEL_MAX;
+  return CreateEngagementScore(url).GetEngagementLevel();

[benwells, 2016/12/09 06:11:23]

It looks like every time something calls CreateEngagementScore it has to have
previously checked if a cleanup is needed. That feels a bit error-prone, is
there a way to make it more robust?

[dominickn, 2016/12/13 06:27:37]

Not quite: OriginsWithMaxDailyEngagement,
GetCountsAndLastVisitForOriginsComplete, and ResetScoreForURL,
SetLastShortcutLaunchTime and CleanupEngagementScores itself all call
CreateEngagementScore without needing to check if a cleanup is needed. We only
need to check for a cleanup if we're about to use the score externally or add
points internally.

[benwells, 2016/12/14 06:17:53]

OK. If it was me I'd try to find a way to clean this up. I think it is tricky
and undiscoverable, and likely to break in future. But it's orthogonal to this
CL.

 }
 
 std::map<GURL, double> SiteEngagementService::GetScoreMap() const {
@@ -166,21 +157,24 @@ bool SiteEngagementService::IsBootstrapped() const {
          SiteEngagementScore::GetBootstrapPoints();
 }
 
-bool SiteEngagementService::IsEngagementAtLeast(const GURL& url,
-                                                EngagementLevel level) const {
+bool SiteEngagementService::IsEngagementAtLeast(
+    const GURL& url,
+    blink::mojom::EngagementLevel level) const {
   DCHECK_LT(SiteEngagementScore::GetMediumEngagementBoundary(),
             SiteEngagementScore::GetHighEngagementBoundary());
   double score = GetScore(url);
   switch (level) {
-    case ENGAGEMENT_LEVEL_NONE:
+    case blink::mojom::EngagementLevel::NONE:
       return true;
-    case ENGAGEMENT_LEVEL_LOW:
+    case blink::mojom::EngagementLevel::MINIMAL:
       return score > 0;
-    case ENGAGEMENT_LEVEL_MEDIUM:
+    case blink::mojom::EngagementLevel::LOW:
+      return score >= 1;
+    case blink::mojom::EngagementLevel::MEDIUM:
       return score >= SiteEngagementScore::GetMediumEngagementBoundary();
-    case ENGAGEMENT_LEVEL_HIGH:
+    case blink::mojom::EngagementLevel::HIGH:
       return score >= SiteEngagementScore::GetHighEngagementBoundary();
-    case ENGAGEMENT_LEVEL_MAX:
+    case blink::mojom::EngagementLevel::MAX:
       return score == SiteEngagementScore::kMaxPoints;
   }
   NOTREACHED();
@@ -219,6 +213,16 @@ void SiteEngagementService::SetLastShortcutLaunchTime(const GURL& url) {
   score.Commit();
 }
 
+void SiteEngagementService::HelperCreated(
+    SiteEngagementService::Helper* helper) {
+  helpers_.insert(helper);
+}
+
+void SiteEngagementService::HelperDeleted(
+    SiteEngagementService::Helper* helper) {
+  helpers_.erase(helper);
+}
+
 double SiteEngagementService::GetScore(const GURL& url) const {
   // Ensure that if engagement is stale, we clean things up before fetching the
   // score.
@@ -259,10 +263,16 @@ void SiteEngagementService::AddPoints(const GURL& url, double points) {
     CleanupEngagementScores(true);
 
   SiteEngagementScore score = CreateEngagementScore(url);
+  blink::mojom::EngagementLevel old_level = score.GetEngagementLevel();
+
   score.AddPoints(points);
   score.Commit();
 
   SetLastEngagementTime(score.last_engagement_time());
+
+  blink::mojom::EngagementLevel new_level = score.GetEngagementLevel();
+  if (old_level != new_level)
+    SendLevelChangeToHelpers(url, new_level);
 }
 
 void SiteEngagementService::AfterStartupTask() {
@@ -484,6 +494,13 @@ void SiteEngagementService::HandleUserInput(
     observer.OnEngagementIncreased(web_contents, url, GetScore(url));
 }
 
+void SiteEngagementService::SendLevelChangeToHelpers(
+    const GURL& url,
+    blink::mojom::EngagementLevel level) {
+  for (SiteEngagementService::Helper* helper : helpers_)
+    helper->OnEngagementLevelChanged(url, level);
+}
+
 bool SiteEngagementService::IsLastEngagementStale() const {
   // Only happens on first run when no engagement has ever been recorded.
   base::Time last_engagement_time = GetLastEngagementTime();