ntp_tiles: Add UMA histograms to correlate icon type to position

components/ntp_tiles/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_tiles/metrics.h"
 
 #include <string>
 
 #include "base/metrics/histogram.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/metrics/sparse_histogram.h"
 #include "base/strings/stringprintf.h"
 #include "components/rappor/public/rappor_utils.h"
 
 namespace ntp_tiles {
 namespace metrics {
 
 namespace {
 
 // Maximum number of tiles to record in histograms.
 const int kMaxNumTiles = 12;
 
 // Identifiers for the various tile sources.
 const char kHistogramClientName[] = "client";
 const char kHistogramServerName[] = "server";
 const char kHistogramPopularName[] = "popular";
 const char kHistogramWhitelistName[] = "whitelist";
 
+// Suffixes for the various icon types.
+const char kIconTypeSuffixColor[] = "IconsColor";
+const char kIconTypeSuffixGray[] = "IconsGray";
+const char kIconTypeSuffixReal[] = "IconsReal";
+
 // Log an event for a given |histogram| at a given element |position|. This
 // routine exists because regular histogram macros are cached thus can't be used
 // if the name of the histogram will change at a given call site.
 void LogHistogramEvent(const std::string& histogram,
                        int position,
                        int num_sites) {
   base::HistogramBase* counter = base::LinearHistogram::FactoryGet(
       histogram, 1, num_sites, num_sites + 1,
       base::Histogram::kUmaTargetedHistogramFlag);
   if (counter)
     counter->Add(position);
 }
 
 std::string GetSourceHistogramName(NTPTileSource source) {
   switch (source) {
     case NTPTileSource::TOP_SITES:
       return kHistogramClientName;
     case NTPTileSource::POPULAR:
       return kHistogramPopularName;
     case NTPTileSource::WHITELIST:
       return kHistogramWhitelistName;
     case NTPTileSource::SUGGESTIONS_SERVICE:
       return kHistogramServerName;
   }
   NOTREACHED();
   return std::string();
 }
 
+const char* GetIconTypeSuffix(MostVisitedTileType type) {
+  switch (type) {
+    case ICON_COLOR:
+      return kIconTypeSuffixColor;
+    case ICON_DEFAULT:
+      return kIconTypeSuffixGray;
+    case ICON_REAL:
+      return kIconTypeSuffixReal;
+    case NONE:                     // Fall through.
+    case NUM_RECORDED_TILE_TYPES:  // Fall through.
+    case THUMBNAIL:                // Fall through.
+    case UNKNOWN_TILE_TYPE:
+      break;
+  }
+  return nullptr;
+}
+
 }  // namespace
 
 void RecordPageImpression(const std::vector<TileImpression>& tiles,
                           rappor::RapporService* rappor_service) {
   UMA_HISTOGRAM_SPARSE_SLOWLY("NewTabPage.NumberOfTiles", tiles.size());
 
   int counts_per_type[NUM_RECORDED_TILE_TYPES] = {0};
   bool have_tile_types = false;
   for (int index = 0; index < static_cast<int>(tiles.size()); index++) {
     NTPTileSource source = tiles[index].source;
@@ skipping 15 matching lines @@
     have_tile_types = true;
     ++counts_per_type[tile_type];
 
     UMA_HISTOGRAM_ENUMERATION("NewTabPage.TileType", tile_type,
                               NUM_RECORDED_TILE_TYPES);
 
     std::string tile_type_histogram =
         base::StringPrintf("NewTabPage.TileType.%s", source_name.c_str());
     LogHistogramEvent(tile_type_histogram, tile_type, NUM_RECORDED_TILE_TYPES);
 
-    switch (tile_type) {
-      case NONE:
-        break;
-      case ICON_COLOR:
-        rappor::SampleDomainAndRegistryFromGURL(
-            rappor_service, "NTP.SuggestionsImpressions.IconsColor", url);
-        break;
-      case ICON_DEFAULT:
-        rappor::SampleDomainAndRegistryFromGURL(
-            rappor_service, "NTP.SuggestionsImpressions.IconsGray", url);
-        break;
-      case ICON_REAL:
-        rappor::SampleDomainAndRegistryFromGURL(
-            rappor_service, "NTP.SuggestionsImpressions.IconsReal", url);
-        break;
-      case NUM_RECORDED_TILE_TYPES:  // Fall through.
-      case THUMBNAIL:  // Fall through.
-      case UNKNOWN_TILE_TYPE:
-        NOTREACHED();
+    const char* icon_type_suffix = GetIconTypeSuffix(tile_type);
+    if (icon_type_suffix) {
+      rappor::SampleDomainAndRegistryFromGURL(
+          rappor_service,
+          base::StringPrintf("NTP.SuggestionsImpressions.%s", icon_type_suffix),
+          url);
+
+      std::string icon_impression_histogram = base::StringPrintf(
+          "NewTabPage.SuggestionsImpression.%s", icon_type_suffix);
+      LogHistogramEvent(icon_impression_histogram, index, kMaxNumTiles);
     }
   }
 
   if (have_tile_types) {
     UMA_HISTOGRAM_SPARSE_SLOWLY("NewTabPage.IconsReal",
                                 counts_per_type[ICON_REAL]);
     UMA_HISTOGRAM_SPARSE_SLOWLY("NewTabPage.IconsColor",
                                 counts_per_type[ICON_COLOR]);
     UMA_HISTOGRAM_SPARSE_SLOWLY("NewTabPage.IconsGray",
                                 counts_per_type[ICON_DEFAULT]);
   }
 }
 
 void RecordTileClick(int index,
                      NTPTileSource source,
                      MostVisitedTileType tile_type) {
   UMA_HISTOGRAM_ENUMERATION("NewTabPage.MostVisited", index, kMaxNumTiles);
 
   std::string histogram = base::StringPrintf(
       "NewTabPage.MostVisited.%s", GetSourceHistogramName(source).c_str());
   LogHistogramEvent(histogram, index, kMaxNumTiles);
 
+  const char* icon_type_suffix = GetIconTypeSuffix(tile_type);
+  if (icon_type_suffix) {
+    std::string icon_histogram =
+        base::StringPrintf("NewTabPage.MostVisited.%s", icon_type_suffix);
+    LogHistogramEvent(icon_histogram, index, kMaxNumTiles);
+  }
+
   if (tile_type < NUM_RECORDED_TILE_TYPES) {
     UMA_HISTOGRAM_ENUMERATION("NewTabPage.TileTypeClicked", tile_type,
                               NUM_RECORDED_TILE_TYPES);
 
     std::string histogram =
         base::StringPrintf("NewTabPage.TileTypeClicked.%s",
                            GetSourceHistogramName(source).c_str());
     LogHistogramEvent(histogram, tile_type, NUM_RECORDED_TILE_TYPES);
   }
 }
 
 }  // namespace metrics
 }  // namespace ntp_tiles