[Suggestions] Remove support for a Control logging group.

chrome/browser/android/most_visited_sites.cc

 // Copyright 2013 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/android/most_visited_sites.h"
 
 #include <string>
 #include <vector>
 
 #include "base/android/jni_android.h"
@@ skipping 43 matching lines @@
 
 // Total number of tiles displayed.
 const char kNumTilesHistogramName[] = "NewTabPage.NumberOfTiles";
 // Tracking thumbnails.
 const char kNumLocalThumbnailTilesHistogramName[] =
     "NewTabPage.NumberOfThumbnailTiles";
 const char kNumEmptyTilesHistogramName[] = "NewTabPage.NumberOfGrayTiles";
 const char kNumServerTilesHistogramName[] = "NewTabPage.NumberOfExternalTiles";
 // Client suggestion opened.
 const char kOpenedItemClientHistogramName[] = "NewTabPage.MostVisited.client";
-// Control group suggestion opened.
-const char kOpenedItemControlHistogramName[] = "NewTabPage.MostVisited.client0";
 // Server suggestion opened, no provider.
 const char kOpenedItemServerHistogramName[] = "NewTabPage.MostVisited.server";
 // Server suggestion opened with provider.
 const char kOpenedItemServerProviderHistogramFormat[] =
     "NewTabPage.MostVisited.server%d";
 // Client impression.
 const char kImpressionClientHistogramName[] =
     "NewTabPage.SuggestionsImpression.client";
-// Control group impression.
-const char kImpressionControlHistogramName[] =
-    "NewTabPage.SuggestionsImpression.client0";
 // Server suggestion impression, no provider.
 const char kImpressionServerHistogramName[] =
     "NewTabPage.SuggestionsImpression.server";
 // Server suggestion impression with provider.
 const char kImpressionServerHistogramFormat[] =
     "NewTabPage.SuggestionsImpression.server%d";
 
 void ExtractMostVisitedTitlesAndURLs(
     const history::MostVisitedURLList& visited_list,
     std::vector<base::string16>* titles,
@@ skipping 95 matching lines @@
     return SyncState::SYNC_OR_HISTORY_SYNC_DISABLED;
   return suggestions::GetSyncState(
       sync->IsSyncEnabledAndLoggedIn(),
       sync->SyncActive() && sync->ConfigurationDone(),
       sync->GetActiveDataTypes().Has(syncer::HISTORY_DELETE_DIRECTIVES));
 }
 
 }  // namespace
 
 MostVisitedSites::MostVisitedSites(Profile* profile)
-    : profile_(profile), num_sites_(0), is_control_group_(false),
-      initial_load_done_(false), num_local_thumbs_(0), num_server_thumbs_(0),
-      num_empty_thumbs_(0), scoped_observer_(this), weak_ptr_factory_(this) {
+    : profile_(profile), num_sites_(0), initial_load_done_(false),
+      num_local_thumbs_(0), num_server_thumbs_(0), num_empty_thumbs_(0),
+      scoped_observer_(this), weak_ptr_factory_(this) {
   // Register the debugging page for the Suggestions Service and the thumbnails
   // debugging page.
   content::URLDataSource::Add(profile_,
                               new suggestions::SuggestionsSource(profile_));
   content::URLDataSource::Add(profile_, new ThumbnailListSource(profile_));
 
   // Register this class as an observer to the sync service. It is important to
   // be notified of changes in the sync state such as initialization, sync
   // being enabled or disabled, etc.
   ProfileSyncService* profile_sync_service =
@@ skipping 104 matching lines @@
       break;
     }
   }
 }
 
 void MostVisitedSites::RecordOpenedMostVisitedItem(JNIEnv* env,
                                                    jobject obj,
                                                    jint index) {
   switch (mv_source_) {
     case TOP_SITES: {
-      const std::string histogram = is_control_group_ ?
-          kOpenedItemControlHistogramName : kOpenedItemClientHistogramName;
-      LogHistogramEvent(histogram, index, num_sites_);
+      UMA_HISTOGRAM_SPARSE_SLOWLY(kOpenedItemClientHistogramName, index);
       break;
     }
     case SUGGESTIONS_SERVICE: {
       if (server_suggestions_.suggestions_size() > index) {
         if (server_suggestions_.suggestions(index).providers_size()) {
           std::string histogram = base::StringPrintf(
               kOpenedItemServerProviderHistogramFormat,
               server_suggestions_.suggestions(index).providers(0));
           LogHistogramEvent(histogram, index, num_sites_);
         } else {
@@ skipping 54 matching lines @@
   std::vector<base::string16> titles;
   std::vector<std::string> urls;
   ExtractMostVisitedTitlesAndURLs(visited_list, &titles, &urls, num_sites);
 
   mv_source_ = TOP_SITES;
 
   // Only log impression metrics on the initial load of the NTP.
   if (!initial_load_done_) {
     int num_tiles = urls.size();
     UMA_HISTOGRAM_SPARSE_SLOWLY(kNumTilesHistogramName, num_tiles);
-    const std::string histogram = is_control_group_ ?
-        kImpressionControlHistogramName : kImpressionClientHistogramName;
     for (int i = 0; i < num_tiles; ++i) {
-      LogHistogramEvent(histogram, i, num_sites_);
+      UMA_HISTOGRAM_SPARSE_SLOWLY(kImpressionClientHistogramName, i);
     }
   }
   initial_load_done_ = true;
 
   JNIEnv* env = AttachCurrentThread();
   Java_MostVisitedURLsObserver_onMostVisitedURLsAvailable(
       env,
       j_observer->obj(),
       ToJavaArrayOfStrings(env, titles).obj(),
       ToJavaArrayOfStrings(env, urls).obj());
 }
 
 void MostVisitedSites::OnSuggestionsProfileAvailable(
     ScopedJavaGlobalRef<jobject>* j_observer,
     const SuggestionsProfile& suggestions_profile) {
-  int size = suggestions_profile.suggestions_size();
-
-  // Determine if the user is in a control group (they would have received
-  // suggestions, but are in a group where they shouldn't).
-  is_control_group_ = size && SuggestionsService::IsControlGroup();
-
-  // If no suggestions data is available or the user is in a control group,
-  // initiate Top Sites query.
-  if (is_control_group_ || !size) {
-    InitiateTopSitesQuery();
-    return;
-  }
-
   std::vector<base::string16> titles;

[huangs, 2015/03/24 15:17:26]

So if size == 0 you no longer need to call InitiateTopSitesQuery()?  Would this
be a change in behavior?

[Mathieu, 2015/03/24 15:26:16]

Done. Gosh, I feel so silly :\

   std::vector<std::string> urls;
-
   int i = 0;
-  for (; i < size && i < num_sites_; ++i) {
+  for (; i < suggestions_profile.suggestions_size() && i < num_sites_; ++i) {
     const ChromeSuggestion& suggestion = suggestions_profile.suggestions(i);
     titles.push_back(base::UTF8ToUTF16(suggestion.title()));
     urls.push_back(suggestion.url());
     // Only log impression metrics on the initial NTP load.
     if (!initial_load_done_) {
       if (suggestion.providers_size()) {
         std::string histogram = base::StringPrintf(
             kImpressionServerHistogramFormat, suggestion.providers(0));
         LogHistogramEvent(histogram, i, num_sites_);
       } else {
@@ skipping 83 matching lines @@
     // The displayed suggestions are invalidated.
     QueryMostVisitedURLs();
   }
 }
 
 static jlong Init(JNIEnv* env, jobject obj, jobject jprofile) {
   MostVisitedSites* most_visited_sites =
       new MostVisitedSites(ProfileAndroid::FromProfileAndroid(jprofile));
   return reinterpret_cast<intptr_t>(most_visited_sites);
 }