Add UMA metrics to the site engagement service.

chrome/browser/engagement/site_engagement_helper.cc

Index: chrome/browser/engagement/site_engagement_helper.cc
diff --git a/chrome/browser/engagement/site_engagement_helper.cc b/chrome/browser/engagement/site_engagement_helper.cc
index a1f83736780589f22a5bc6319c84fc925f902727..1d52a82c7d112850de13fcd76fa7ccc0bb5bdffd 100644
--- a/chrome/browser/engagement/site_engagement_helper.cc
+++ b/chrome/browser/engagement/site_engagement_helper.cc
@@ -47,7 +47,7 @@ bool SiteEngagementHelper::InputTracker::HandleKeyPressEvent(
   // (e.g. keypress is a key down then key up).
   if (event.type == blink::WebInputEvent::RawKeyDown) {
     PauseTracking(helper_->web_contents()->GetRenderViewHost());
-    helper_->RecordUserInput();
+    helper_->RecordUserInput(SiteEngagementMetrics::ENGAGEMENT_KEYPRESS);
   }
   return false;
 }
@@ -61,7 +61,7 @@ bool SiteEngagementHelper::InputTracker::HandleMouseEvent(
        event.type == blink::WebInputEvent::MouseDown) ||
       event.type == blink::WebInputEvent::MouseWheel) {
     PauseTracking(helper_->web_contents()->GetRenderViewHost());
-    helper_->RecordUserInput();
+    helper_->RecordUserInput(SiteEngagementMetrics::ENGAGEMENT_MOUSE);
   }
   return false;
 }
@@ -125,7 +125,8 @@ SiteEngagementHelper::SiteEngagementHelper(content::WebContents* contents)
       input_tracker_(new InputTracker(this)),
       record_engagement_(false) { }
 
-void SiteEngagementHelper::RecordUserInput() {
+void SiteEngagementHelper::RecordUserInput(
+    SiteEngagementMetrics::EngagementType type) {
   TRACE_EVENT0("SiteEngagement", "RecordUserInput");
   content::WebContents* contents = web_contents();
   if (contents) {
@@ -136,6 +137,7 @@ void SiteEngagementHelper::RecordUserInput() {
 
     // Service is null in incognito.
     if (service) {
+      SiteEngagementMetrics::RecordEngagement(type);
       service->HandleUserInput(contents->GetVisibleURL());
       FOR_EACH_OBSERVER(Observer, observer_list_, OnInputRecorded(this));
     }
@@ -159,8 +161,11 @@ void SiteEngagementHelper::DidNavigateMainFrame(
   SiteEngagementService* service =
       SiteEngagementServiceFactory::GetForProfile(profile);
 
-  if (service)
+  if (service) {
+    SiteEngagementMetrics::RecordEngagement(
+        SiteEngagementMetrics::ENGAGEMENT_NAVIGATION);

[calamity, 2015/09/25 07:08:33]

I think we should do this in HandleNavigation() in case we decide to separate
different navigations.

[dominickn, 2015/09/28 03:34:50]

It would be inconsistent to have the user input UMA logged in the helper but the
navigation UMA logged in the service. I think if we split out different
navigations we can simply do like the user input UMA does here and directly log
the transition type in the helper rather than sending it into the service.

[calamity, 2015/09/28 07:33:47]

Hmm, I'd prefer all our logging take place in the same place. In fact, even the
engagement type above ought to be passed into the SiteEngagementService.

I think this class should remain as much as possible a pure input to
SiteEngagementService rather than something that thinks about any sort of real
logic.

     service->HandleNavigation(params.url, params.transition);
+  }
 
   input_tracker_->StartTracking(contents->GetRenderViewHost());
 }