Add UMA metrics to the site engagement service.

chrome/browser/engagement/site_engagement_service_browsertest.cc

Index: chrome/browser/engagement/site_engagement_service_browsertest.cc
diff --git a/chrome/browser/engagement/site_engagement_service_browsertest.cc b/chrome/browser/engagement/site_engagement_service_browsertest.cc
index 096ea82dbb4bef9b01a61318c63baa7368860dee..2c82e771aa6be5e9858926e2535177d8a7f1c44e 100644
--- a/chrome/browser/engagement/site_engagement_service_browsertest.cc
+++ b/chrome/browser/engagement/site_engagement_service_browsertest.cc
@@ -6,6 +6,7 @@
 #include "base/run_loop.h"
 #include "base/single_thread_task_runner.h"
 #include "base/task_runner.h"
+#include "base/test/histogram_tester.h"
 #include "base/test/simple_test_clock.h"
 #include "base/thread_task_runner_handle.h"
 #include "base/timer/mock_timer.h"
@@ -32,8 +33,8 @@ class TestSiteEngagementHelper : public SiteEngagementHelper {
 
   ~TestSiteEngagementHelper() override { }
 
-  void RecordUserInput() override {
-    SiteEngagementHelper::RecordUserInput();
+  void RecordUserInput(SiteEngagementMetrics::EngagementType type) override {
+    SiteEngagementHelper::RecordUserInput(type);
     base::ThreadTaskRunnerHandle::Get()->PostTask(FROM_HERE, quit_closure_);
   }
 
@@ -209,9 +210,19 @@ IN_PROC_BROWSER_TEST_F(SiteEngagementServiceBrowserTest,
     SiteEngagementServiceFactory::GetForProfile(browser()->profile());
   DCHECK(service);
 
+  base::HistogramTester histograms;
+
+  // Histograms should start off empty.
+  histograms.ExpectTotalCount(SiteEngagementMetrics::kEngagementTypeHistogram,
+                              0);
+
   ui_test_utils::NavigateToURL(browser(), url1);
   EXPECT_DOUBLE_EQ(0.5, service->GetScore(url1));
   EXPECT_EQ(0, service->GetScore(url2));
+  histograms.ExpectTotalCount(SiteEngagementMetrics::kEngagementTypeHistogram,
+                              1);
+  histograms.ExpectBucketCount(SiteEngagementMetrics::kEngagementTypeHistogram,
+                               SiteEngagementMetrics::ENGAGEMENT_NAVIGATION, 1);
 
   HandleKeyPress(helper.get(), ui::VKEY_UP);
   HandleKeyPress(helper.get(), ui::VKEY_RETURN);
@@ -222,6 +233,14 @@ IN_PROC_BROWSER_TEST_F(SiteEngagementServiceBrowserTest,
 
   EXPECT_DOUBLE_EQ(0.7, service->GetScore(url1));
   EXPECT_EQ(0, service->GetScore(url2));
+  histograms.ExpectTotalCount(SiteEngagementMetrics::kEngagementTypeHistogram,
+                              5);
+  histograms.ExpectBucketCount(SiteEngagementMetrics::kEngagementTypeHistogram,
+                               SiteEngagementMetrics::ENGAGEMENT_NAVIGATION, 1);
+  histograms.ExpectBucketCount(SiteEngagementMetrics::kEngagementTypeHistogram,
+                               SiteEngagementMetrics::ENGAGEMENT_KEYPRESS, 3);
+  histograms.ExpectBucketCount(SiteEngagementMetrics::kEngagementTypeHistogram,
+                               SiteEngagementMetrics::ENGAGEMENT_MOUSE, 1);
 
   HandleMouseEvent(helper.get(), blink::WebMouseEvent::ButtonRight,
                    blink::WebInputEvent::MouseDown);
@@ -232,6 +251,10 @@ IN_PROC_BROWSER_TEST_F(SiteEngagementServiceBrowserTest,
 
   EXPECT_DOUBLE_EQ(0.85, service->GetScore(url1));
   EXPECT_EQ(0, service->GetScore(url2));
+  histograms.ExpectTotalCount(SiteEngagementMetrics::kEngagementTypeHistogram,
+                              8);
+  histograms.ExpectBucketCount(SiteEngagementMetrics::kEngagementTypeHistogram,
+                               SiteEngagementMetrics::ENGAGEMENT_MOUSE, 4);
 
   ui_test_utils::NavigateToURL(browser(), url2);
 
@@ -246,6 +269,14 @@ IN_PROC_BROWSER_TEST_F(SiteEngagementServiceBrowserTest,
   EXPECT_DOUBLE_EQ(0.85, service->GetScore(url1));
   EXPECT_DOUBLE_EQ(0.6, service->GetScore(url2));
   EXPECT_DOUBLE_EQ(1.45, service->GetTotalEngagementPoints());
+  histograms.ExpectTotalCount(SiteEngagementMetrics::kEngagementTypeHistogram,
+                              11);
+  histograms.ExpectBucketCount(SiteEngagementMetrics::kEngagementTypeHistogram,
+                               SiteEngagementMetrics::ENGAGEMENT_NAVIGATION, 2);
+  histograms.ExpectBucketCount(SiteEngagementMetrics::kEngagementTypeHistogram,
+                               SiteEngagementMetrics::ENGAGEMENT_KEYPRESS, 4);
+  histograms.ExpectBucketCount(SiteEngagementMetrics::kEngagementTypeHistogram,
+                               SiteEngagementMetrics::ENGAGEMENT_MOUSE, 5);
 }
 
 IN_PROC_BROWSER_TEST_F(SiteEngagementServiceBrowserTest,