[Most Visited] Removing Most Visited Tiles experiment code, which is obsolete.

chrome/browser/history/most_visited_tiles_experiment.cc

Index: chrome/browser/history/most_visited_tiles_experiment.cc
diff --git a/chrome/browser/history/most_visited_tiles_experiment.cc b/chrome/browser/history/most_visited_tiles_experiment.cc
deleted file mode 100644
index 4a85dfd2554e3f6b1e52eed0daf9d36a78837b65..0000000000000000000000000000000000000000
--- a/chrome/browser/history/most_visited_tiles_experiment.cc
+++ /dev/null
@@ -1,124 +0,0 @@
-// 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/history/most_visited_tiles_experiment.h"
-
-#include "base/metrics/field_trial.h"
-#include "base/metrics/histogram.h"
-#include "base/strings/string_util.h"
-#include "chrome/common/instant_types.h"
-
-namespace history {
-
-namespace {
-
-// Constants for the most visited tile placement field trial.
-// ex:
-// "OneEightGroup_Flipped" --> Will cause tile 1 and 8 to be flipped.
-// "OneEightGroup_NoChange" --> Will not flip anything.
-//
-// See field trial config (MostVisitedTilePlacement.json) for details.
-const char kMostVisitedFieldTrialName[] = "MostVisitedTilePlacement";
-// Name of histogram tracking types of actions carried out by the field trial.
-const char kMostVisitedExperimentHistogramName[] =
-    "NewTabPage.MostVisitedTilePlacementExperiment";
-const char kOneEightGroupPrefix[] = "OneEight";
-const char kOneFourGroupPrefix[] = "OneFour";
-const char kFlippedSuffix[] = "Flipped";
-const char kDontShowOpenURLsGroupName[] = "DontShowOpenTabs";
-// Minimum number of Most Visited suggestions required in order for the Most
-// Visited Field Trial to remove a URL already open in the browser.
-const size_t kMinUrlSuggestions = 8;
-
-}  // namespace
-
-// static
-void MostVisitedTilesExperiment::MaybeShuffle(MostVisitedURLList* data) {
-  const std::string group_name =
-      base::FieldTrialList::FindFullName(kMostVisitedFieldTrialName);
-
-  // Depending on the study group of the client, we might flip the 1st and 4th
-  // tiles, or the 1st and 8th, or do nothing.
-  if (!EndsWith(group_name, kFlippedSuffix, true))
-    return;
-
-  size_t index_to_flip = 0;
-  if (StartsWithASCII(group_name, kOneEightGroupPrefix, true)) {
-    if (data->size() < 8) {
-      LogInHistogram(NTP_TILE_EXPERIMENT_ACTION_TOO_FEW_URLS_TILES_1_8);
-      return;
-    }
-    index_to_flip = 7;
-  } else if (StartsWithASCII(group_name, kOneFourGroupPrefix, true)) {
-    if (data->size() < 4) {
-      LogInHistogram(NTP_TILE_EXPERIMENT_ACTION_TOO_FEW_URLS_TILES_1_4);
-      return;
-    }
-    index_to_flip = 3;
-  }
-  std::swap((*data)[0], (*data)[index_to_flip]);
-}
-
-// static
-bool MostVisitedTilesExperiment::IsDontShowOpenURLsEnabled() {
-  return base::FieldTrialList::FindFullName(kMostVisitedFieldTrialName) ==
-      kDontShowOpenURLsGroupName;
-}
-
-// static
-void MostVisitedTilesExperiment::RemoveItemsMatchingOpenTabs(
-    const std::set<std::string>& open_urls,
-    std::vector<InstantMostVisitedItem>* items) {
-  for (size_t i = 0; i < items->size(); ) {
-    const std::string& url = (*items)[i].url.spec();
-    if (ShouldRemoveURL(open_urls, url, items->size()))
-      items->erase(items->begin() + i);
-    else
-      ++i;
-  }
-}
-
-// static
-void MostVisitedTilesExperiment::RemovePageValuesMatchingOpenTabs(
-    const std::set<std::string>& open_urls,
-    base::ListValue* pages_value) {
-  for (size_t i = 0; i < pages_value->GetSize(); ) {
-    base::DictionaryValue* page_value;
-    std::string url;
-    if (pages_value->GetDictionary(i, &page_value) &&
-        page_value->GetString("url", &url) &&
-        ShouldRemoveURL(open_urls, url, pages_value->GetSize())) {
-      pages_value->Remove(*page_value, &i);
-    } else {
-      ++i;
-    }
-  }
-}
-
-// static
-void MostVisitedTilesExperiment::LogInHistogram(
-    NtpTileExperimentActions action) {
-  UMA_HISTOGRAM_ENUMERATION(kMostVisitedExperimentHistogramName,
-                            action,
-                            NUM_NTP_TILE_EXPERIMENT_ACTIONS);
-}
-
-// static
-bool MostVisitedTilesExperiment::ShouldRemoveURL(
-    const std::set<std::string>& open_urls,
-    const std::string& url,
-    const size_t size) {
-  if (open_urls.count(url) == 0)
-    return false;
-
-  if (size <= kMinUrlSuggestions) {
-    LogInHistogram(NTP_TILE_EXPERIMENT_ACTION_DID_NOT_REMOVE_URL);
-    return false;
-  }
-
-  LogInHistogram(NTP_TILE_EXPERIMENT_ACTION_REMOVED_URL);
-  return true;
-}
-
-}  // namespace history