Add UMA metrics to the site engagement service.

chrome/browser/engagement/site_engagement_metrics.cc

Index: chrome/browser/engagement/site_engagement_metrics.cc
diff --git a/chrome/browser/engagement/site_engagement_metrics.cc b/chrome/browser/engagement/site_engagement_metrics.cc
new file mode 100644
index 0000000000000000000000000000000000000000..504be91cbdf156acec500e8431132ddf1771edd4
--- /dev/null
+++ b/chrome/browser/engagement/site_engagement_metrics.cc
@@ -0,0 +1,73 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/browser/engagement/site_engagement_metrics.h"
+
+#include "base/metrics/histogram_macros.h"
+#include "base/metrics/sparse_histogram.h"
+
+namespace {
+
+const char kTotalEngagementHistogram[] =
+    "SiteEngagementService.TotalEngagement";
+
+const char kTotalOriginsHistogram[] = "SiteEngagementService.OriginsEngaged";
+
+const char kEngagementByOriginHistogram[] =
+    "SiteEngagementService.EngagementByOrigin";
+
+const char kOriginsWithMaxEngagementHistogram[] =
+    "SiteEngagementService.OriginsWithMaxEngagement";
+
+const char kOriginsWithMaxDailyEngagementHistogram[] =
+    "SiteEngagementService.OriginsWithMaxDailyEngagement";
+
+const char kEngagementTypeHistogram[] = "SiteEngagementService.EngagementType";
+
+}  // namespace
+
+void SiteEngagementMetrics::RecordTotalSiteEngagement(
+    double total_engagement) {
+  UMA_HISTOGRAM_COUNTS_10000(kTotalEngagementHistogram, total_engagement);
+}
+
+void SiteEngagementMetrics::RecordTotalOriginsEngaged(int num_origins) {
+  UMA_HISTOGRAM_COUNTS_10000(kTotalOriginsHistogram, num_origins);
+}
+
+void SiteEngagementMetrics::RecordEngagementByOrigin(
+    std::map<GURL, double> score_map) {
+  for (const auto& value: score_map) {
+    UMA_HISTOGRAM_COUNTS_100(kEngagementByOriginHistogram, value.second);
+  }
+}
+
+void SiteEngagementMetrics::RecordOriginsWithMaxEngagement(int total_origins) {
+  UMA_HISTOGRAM_COUNTS_100(kOriginsWithMaxEngagementHistogram, total_origins);
+}
+
+void SiteEngagementMetrics::RecordOriginsWithMaxDailyEngagement(
+    int total_origins) {
+  UMA_HISTOGRAM_COUNTS_100(kOriginsWithMaxDailyEngagementHistogram,
+                           total_origins);
+}
+
+void SiteEngagementMetrics::RecordEngagement(EngagementType type) {
+  switch (type) {
+    case ENGAGEMENT_NAVIGATION:
+      UMA_HISTOGRAM_SPARSE_SLOWLY(kEngagementTypeHistogram,
+                                  ENGAGEMENT_NAVIGATION);
+      break;
+    case ENGAGEMENT_KEYPRESS:
+      UMA_HISTOGRAM_SPARSE_SLOWLY(kEngagementTypeHistogram,
+                                  ENGAGEMENT_KEYPRESS);
+      break;
+    case ENGAGEMENT_MOUSE:
+      UMA_HISTOGRAM_SPARSE_SLOWLY(kEngagementTypeHistogram, ENGAGEMENT_MOUSE);
+      break;
+    default:
+      NOTREACHED() << "Invalid type passed to RecordUserInput().";
+      break;
+  }
+}