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

chrome/browser/android/ntp/ntp_snippets_bridge.cc

Index: chrome/browser/android/ntp/ntp_snippets_bridge.cc
diff --git a/chrome/browser/android/ntp/ntp_snippets_bridge.cc b/chrome/browser/android/ntp/ntp_snippets_bridge.cc
index 939435eba8b2a60d840dfae30e1cad96a0af49e6..b61791e57f7eb02b96a957c9d7a0cf4fe251f8fb 100644
--- a/chrome/browser/android/ntp/ntp_snippets_bridge.cc
+++ b/chrome/browser/android/ntp/ntp_snippets_bridge.cc
@@ -5,6 +5,7 @@
 #include "chrome/browser/android/ntp/ntp_snippets_bridge.h"
 
 #include <jni.h>
+#include <algorithm>
 #include <utility>
 #include <vector>
 
@@ -13,6 +14,7 @@
 #include "base/android/jni_array.h"
 #include "base/android/jni_string.h"
 #include "base/callback.h"
+#include "base/stl_util.h"
 #include "base/time/time.h"
 #include "chrome/browser/history/history_service_factory.h"
 #include "chrome/browser/ntp_snippets/content_suggestions_service_factory.h"
@@ -107,6 +109,16 @@ ntp_snippets::RemoteSuggestionsScheduler* GetRemoteSuggestionsScheduler() {
   return content_suggestions_service->remote_suggestions_scheduler();
 }
 
+int GetCategoryPosition(
+    Category category,
+    const ntp_snippets::ContentSuggestionsService* service) {
+  std::vector<Category> ordered_categories = service->GetCategories();
+  DCHECK(base::ContainsValue(ordered_categories, category));
+  auto it =
+      std::find(ordered_categories.begin(), ordered_categories.end(), category);
+  return it - ordered_categories.begin();
+}

[noyau (Ping after 24h), 2017/01/05 14:38:04]

Can this lookup can be done by the metrics code in component instead of here to
avoid code duplication with non android UI?

[vitaliii, 2017/01/05 15:16:59]

Done.

[jkrcal, 2017/01/05 15:18:08]

I am not sure this is the right way, since metrics code would need a pointer to
ContentSuggestionsService in OnSuggestionOpened(). To me, this seems even more
ugly than code duplication.

Do you insist?

[vitaliii, 2017/01/05 15:47:37]

Acknowledged.

+
 }  // namespace
 
 static jlong Init(JNIEnv* env,
@@ -264,7 +276,7 @@ void NTPSnippetsBridge::DismissSuggestion(
     const JavaParamRef<jstring>& jurl,
     jint global_position,
     jint j_category_id,
-    jint category_position,
+    jint position_in_category,
     const JavaParamRef<jstring>& id_within_category) {
   Category category = Category::FromIDValue(j_category_id);
 
@@ -274,14 +286,14 @@ void NTPSnippetsBridge::DismissSuggestion(
   history_service_->QueryURL(
       GURL(ConvertJavaStringToUTF8(env, jurl)), /*want_visits=*/false,
       base::Bind(
-          [](int global_position, Category category, int category_position,
+          [](int global_position, Category category, int position_in_category,
              bool success, const history::URLRow& row,
              const history::VisitVector& visit_vector) {
             bool visited = success && row.visit_count() != 0;
             ntp_snippets::metrics::OnSuggestionDismissed(
-                global_position, category, category_position, visited);
+                global_position, category, position_in_category, visited);
           },
-          global_position, category, category_position),
+          global_position, category, position_in_category),
       &tracker_);
 }
 
@@ -327,7 +339,7 @@ void NTPSnippetsBridge::OnSuggestionShown(JNIEnv* env,
                                           const JavaParamRef<jobject>& obj,
                                           jint global_position,
                                           jint j_category_id,
-                                          jint category_position,
+                                          jint position_in_category,
                                           jlong publish_timestamp_ms,
                                           jfloat score) {
   PrefService* pref_service = ProfileManager::GetLastUsedProfile()->GetPrefs();
@@ -336,8 +348,8 @@ void NTPSnippetsBridge::OnSuggestionShown(JNIEnv* env,
           ntp_snippets::prefs::kLastSuccessfulBackgroundFetchTime));
 
   ntp_snippets::metrics::OnSuggestionShown(
-      global_position, Category::FromIDValue(j_category_id), category_position,
-      base::Time::FromJavaTime(publish_timestamp_ms),
+      global_position, Category::FromIDValue(j_category_id),
+      position_in_category, base::Time::FromJavaTime(publish_timestamp_ms),
       last_background_fetch_time, score);
   if (global_position == 0) {
     content_suggestions_service_->user_classifier()->OnEvent(
@@ -349,19 +361,20 @@ void NTPSnippetsBridge::OnSuggestionOpened(JNIEnv* env,
                                            const JavaParamRef<jobject>& obj,
                                            jint global_position,
                                            jint j_category_id,
-                                           jint category_position,
+                                           jint position_in_category,
                                            jlong publish_timestamp_ms,
                                            jfloat score,
                                            int windowOpenDisposition) {
+  const Category category = Category::FromIDValue(j_category_id);
   ntp_snippets::metrics::OnSuggestionOpened(
-      global_position, Category::FromIDValue(j_category_id), category_position,
-      base::Time::FromJavaTime(publish_timestamp_ms), score,
-      static_cast<WindowOpenDisposition>(windowOpenDisposition));
+      global_position, category,
+      GetCategoryPosition(category, content_suggestions_service_),
+      position_in_category, base::Time::FromJavaTime(publish_timestamp_ms),
+      score, static_cast<WindowOpenDisposition>(windowOpenDisposition));
   // TODO(vitaliii): Add ContentSuggestionsService::OnSuggestionOpened and
   // notify the ranker and the classifier there instead. Do not expose both of
   // them at all. See crbug.com/674080.
-  content_suggestions_service_->category_ranker()->OnSuggestionOpened(
-      Category::FromIDValue(j_category_id));
+  content_suggestions_service_->category_ranker()->OnSuggestionOpened(category);
   content_suggestions_service_->user_classifier()->OnEvent(
       ntp_snippets::UserClassifier::Metric::SUGGESTIONS_USED);
 }
@@ -370,12 +383,13 @@ void NTPSnippetsBridge::OnSuggestionMenuOpened(JNIEnv* env,
                                                const JavaParamRef<jobject>& obj,
                                                jint global_position,
                                                jint j_category_id,
-                                               jint category_position,
+                                               jint position_in_category,
                                                jlong publish_timestamp_ms,
                                                jfloat score) {
   ntp_snippets::metrics::OnSuggestionMenuOpened(
-      global_position, Category::FromIDValue(j_category_id), category_position,
-      base::Time::FromJavaTime(publish_timestamp_ms), score);
+      global_position, Category::FromIDValue(j_category_id),
+      position_in_category, base::Time::FromJavaTime(publish_timestamp_ms),
+      score);
 }
 
 void NTPSnippetsBridge::OnMoreButtonShown(JNIEnv* env,