[NTP::SectionOrder] Add category position metric for opened suggestions.

components/ntp_snippets/content_suggestions_metrics.cc

 // Copyright 2016 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 "components/ntp_snippets/content_suggestions_metrics.h"
 
 #include <cmath>
 #include <string>
 #include <type_traits>
 
 #include "base/metrics/histogram.h"
 #include "base/metrics/histogram_functions.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/metrics/user_metrics.h"
 #include "base/strings/stringprintf.h"
 #include "base/template_util.h"
 
 namespace ntp_snippets {
 namespace metrics {
 
 namespace {
 
 const int kMaxSuggestionsPerCategory = 10;
 const int kMaxSuggestionsTotal = 50;
+const int kMaxCategories = 10;
 
 const char kHistogramCountOnNtpOpened[] =
     "NewTabPage.ContentSuggestions.CountOnNtpOpened";
 const char kHistogramShown[] = "NewTabPage.ContentSuggestions.Shown";
 const char kHistogramShownAge[] = "NewTabPage.ContentSuggestions.ShownAge";
 const char kHistogramShownScore[] =
     "NewTabPage.ContentSuggestions.ShownScoreNormalized";
 const char kHistogramOpened[] = "NewTabPage.ContentSuggestions.Opened";
 const char kHistogramOpenedAge[] = "NewTabPage.ContentSuggestions.OpenedAge";
+const char kHistogramOpenedCategoryIndex[] =
+    "NewTabPage.ContentSuggestions.OpenedCategoryIndex";
 const char kHistogramOpenedScore[] =
     "NewTabPage.ContentSuggestions.OpenedScoreNormalized";
 const char kHistogramOpenDisposition[] =
     "NewTabPage.ContentSuggestions.OpenDisposition";
 const char kHistogramMenuOpened[] = "NewTabPage.ContentSuggestions.MenuOpened";
 const char kHistogramMenuOpenedAge[] =
     "NewTabPage.ContentSuggestions.MenuOpenedAge";
 const char kHistogramMenuOpenedScore[] =
     "NewTabPage.ContentSuggestions.MenuOpenedScoreNormalized";
 const char kHistogramDismissedUnvisited[] =
@@ skipping 165 matching lines @@
     LogCategoryHistogramPosition(kHistogramCountOnNtpOpened, item.first,
                                  item.second, kMaxSuggestionsPerCategory);
     suggestions_total += item.second;
   }
   UMA_HISTOGRAM_EXACT_LINEAR(kHistogramCountOnNtpOpened, suggestions_total,
                              kMaxSuggestionsTotal);
 }
 
 void OnSuggestionShown(int global_position,
                        Category category,
-                       int category_position,
+                       int position_in_category,
                        base::Time publish_date,
                        base::Time last_background_fetch_time,
                        float score) {
   UMA_HISTOGRAM_EXACT_LINEAR(kHistogramShown, global_position,
                              kMaxSuggestionsTotal);
-  LogCategoryHistogramPosition(kHistogramShown, category, category_position,
+  LogCategoryHistogramPosition(kHistogramShown, category, position_in_category,
                                kMaxSuggestionsPerCategory);
 
   base::TimeDelta age = base::Time::Now() - publish_date;
   LogCategoryHistogramAge(kHistogramShownAge, category, age);
 
   LogCategoryHistogramScore(kHistogramShownScore, category, score);
 
   // TODO(markusheintz): Discuss whether the code below should be move into a
   // separate method called OnSuggestionsListShown.
   // When the first of the articles suggestions is shown, then we count this as
   // a single usage of content suggestions.
   if (category.IsKnownCategory(KnownCategories::ARTICLES) &&
-      category_position == 0) {
+      position_in_category == 0) {
     RecordContentSuggestionsUsage();
 
     // Records the time since the last background fetch of the remote content
     // suggestions.
     UMA_HISTOGRAM_CUSTOM_TIMES(
         kHistogramContentSuggestionsTimeSinceLastBackgroundFetch,
         base::Time::Now() - last_background_fetch_time,
         base::TimeDelta::FromSeconds(1), base::TimeDelta::FromDays(7),
         /*bucket_count=*/100);
   }
 }
 
 void OnSuggestionOpened(int global_position,
                         Category category,
-                        int category_position,
+                        int category_index,
+                        int position_in_category,
                         base::Time publish_date,
                         float score,
                         WindowOpenDisposition disposition) {
+  UMA_HISTOGRAM_EXACT_LINEAR(kHistogramOpenedCategoryIndex, category_index,
+                             kMaxCategories);
+  LogCategoryHistogramPosition(kHistogramOpenedCategoryIndex, category,
+                               category_index, kMaxCategories);
+
   UMA_HISTOGRAM_EXACT_LINEAR(kHistogramOpened, global_position,
                              kMaxSuggestionsTotal);
-  LogCategoryHistogramPosition(kHistogramOpened, category, category_position,
+  LogCategoryHistogramPosition(kHistogramOpened, category, position_in_category,
                                kMaxSuggestionsPerCategory);
 
   base::TimeDelta age = base::Time::Now() - publish_date;
   LogCategoryHistogramAge(kHistogramOpenedAge, category, age);
 
   LogCategoryHistogramScore(kHistogramOpenedScore, category, score);
 
   // We use WindowOpenDisposition::MAX_VALUE + 1 for |value_max| since MAX_VALUE
   // itself is a valid (and used) enum value.
   UMA_HISTOGRAM_EXACT_LINEAR(
       kHistogramOpenDisposition, static_cast<int>(disposition),
       static_cast<int>(WindowOpenDisposition::MAX_VALUE) + 1);
   base::UmaHistogramExactLinear(
       GetCategoryHistogramName(kHistogramOpenDisposition, category),
       static_cast<int>(disposition),
       static_cast<int>(WindowOpenDisposition::MAX_VALUE) + 1);
 
   if (category.IsKnownCategory(KnownCategories::ARTICLES)) {
     RecordContentSuggestionsUsage();
   }
 }
 
 void OnSuggestionMenuOpened(int global_position,
                             Category category,
-                            int category_position,
+                            int position_in_category,
                             base::Time publish_date,
                             float score) {
   UMA_HISTOGRAM_EXACT_LINEAR(kHistogramMenuOpened, global_position,
                              kMaxSuggestionsTotal);
   LogCategoryHistogramPosition(kHistogramMenuOpened, category,
-                               category_position, kMaxSuggestionsPerCategory);
+                               position_in_category,
+                               kMaxSuggestionsPerCategory);
 
   base::TimeDelta age = base::Time::Now() - publish_date;
   LogCategoryHistogramAge(kHistogramMenuOpenedAge, category, age);
 
   LogCategoryHistogramScore(kHistogramMenuOpenedScore, category, score);
 }
 
 void OnSuggestionDismissed(int global_position,
                            Category category,
-                           int category_position,
+                           int position_in_category,
                            bool visited) {
   if (visited) {
     UMA_HISTOGRAM_EXACT_LINEAR(kHistogramDismissedVisited, global_position,
                                kMaxSuggestionsTotal);
     LogCategoryHistogramPosition(kHistogramDismissedVisited, category,
-                                 category_position, kMaxSuggestionsPerCategory);
+                                 position_in_category,
+                                 kMaxSuggestionsPerCategory);
   } else {
     UMA_HISTOGRAM_EXACT_LINEAR(kHistogramDismissedUnvisited, global_position,
                                kMaxSuggestionsTotal);
     LogCategoryHistogramPosition(kHistogramDismissedUnvisited, category,
-                                 category_position, kMaxSuggestionsPerCategory);
+                                 position_in_category,
+                                 kMaxSuggestionsPerCategory);
   }
 }
 
 void OnSuggestionTargetVisited(Category category, base::TimeDelta visit_time) {
   std::string name =
       GetCategoryHistogramName(kHistogramVisitDuration, category);
   base::UmaHistogramLongTimes(name, visit_time);
 }
 
 void OnMoreButtonShown(Category category, int position) {
@@ skipping 11 matching lines @@
 }
 
 void OnCategoryDismissed(Category category) {
   UMA_HISTOGRAM_ENUMERATION(kHistogramCategoryDismissed,
                             GetHistogramCategory(category),
                             HistogramCategories::COUNT);
 }
 
 }  // namespace metrics
 }  // namespace ntp_snippets