[Most Visited] Only log impression metrics on initial NTP load.

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 173 matching lines @@
   return suggestions::GetSyncState(
       sync->IsSyncEnabledAndLoggedIn(),
       sync->SyncActive(),
       sync->GetActiveDataTypes().Has(syncer::HISTORY_DELETE_DIRECTIVES));
 }
 
 }  // namespace
 
 MostVisitedSites::MostVisitedSites(Profile* profile)
     : profile_(profile), num_sites_(0), is_control_group_(false),
-      num_local_thumbs_(0), num_server_thumbs_(0), num_empty_thumbs_(0),
-      weak_ptr_factory_(this) {
+      initial_load_done_(false), num_local_thumbs_(0), num_server_thumbs_(0),
+      num_empty_thumbs_(0), 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 186 matching lines @@
 void MostVisitedSites::OnMostVisitedURLsAvailable(
     ScopedJavaGlobalRef<jobject>* j_observer,
     int num_sites,
     const history::MostVisitedURLList& visited_list) {
   std::vector<base::string16> titles;
   std::vector<std::string> urls;
   ExtractMostVisitedTitlesAndURLs(visited_list, &titles, &urls, num_sites);
 
   mv_source_ = TOP_SITES;
 
-  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_);
+  // 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_);
+    }
   }
+  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(
@@ skipping 13 matching lines @@
   }
 
   std::vector<base::string16> titles;
   std::vector<std::string> urls;
 
   int i = 0;
   for (; i < size && i < num_sites_; ++i) {
     const ChromeSuggestion& suggestion = suggestions_profile.suggestions(i);
     titles.push_back(base::UTF8ToUTF16(suggestion.title()));
     urls.push_back(suggestion.url());
-    if (suggestion.providers_size()) {
-      std::string histogram = base::StringPrintf(
-          kImpressionServerHistogramFormat, suggestion.providers(0));
-      LogHistogramEvent(histogram, i, num_sites_);
-    } else {
-      UMA_HISTOGRAM_SPARSE_SLOWLY(kImpressionServerHistogramName, i);
+    // 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 {
+        UMA_HISTOGRAM_SPARSE_SLOWLY(kImpressionServerHistogramName, i);
+      }
     }
   }
-  UMA_HISTOGRAM_SPARSE_SLOWLY(kNumTilesHistogramName, i);
+  if (!initial_load_done_) {
+    UMA_HISTOGRAM_SPARSE_SLOWLY(kNumTilesHistogramName, i);
+  }
+  initial_load_done_ = true;
 
   mv_source_ = SUGGESTIONS_SERVICE;
   // Keep a copy of the suggestions for eventual logging.
   server_suggestions_ = suggestions_profile;
 
   JNIEnv* env = AttachCurrentThread();
   Java_MostVisitedURLsObserver_onMostVisitedURLsAvailable(
       env,
       j_observer->obj(),
       ToJavaArrayOfStrings(env, titles).obj(),
@@ skipping 55 matching lines @@
   num_empty_thumbs_ = 0;
   UMA_HISTOGRAM_SPARSE_SLOWLY(kNumServerTilesHistogramName, num_server_thumbs_);
   num_server_thumbs_ = 0;
 }
 
 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);
 }