[Most Visited] Removing Most Visited Tiles experiment code, which is obsolete.

chrome/browser/history/most_visited_tiles_experiment.h

-// 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.
-
-#ifndef CHROME_BROWSER_HISTORY_MOST_VISITED_TILES_EXPERIMENT_H_
-#define CHROME_BROWSER_HISTORY_MOST_VISITED_TILES_EXPERIMENT_H_
-
-#include "base/values.h"
-#include "chrome/browser/history/history_types.h"
-#include "chrome/common/instant_types.h"
-
-namespace history {
-
-// This enum is also defined in histograms.xml. These values represent the
-// types of actions carried out by the Most Visited Tile Placement experiment.
-enum NtpTileExperimentActions {
-  NTP_TILE_EXPERIMENT_ACTION_REMOVED_URL = 0,
-  NTP_TILE_EXPERIMENT_ACTION_DID_NOT_REMOVE_URL = 1,
-  NTP_TILE_EXPERIMENT_ACTION_TOO_FEW_URLS_TILES_1_8 = 2,
-  NTP_TILE_EXPERIMENT_ACTION_TOO_FEW_URLS_TILES_1_4 = 3,
-  // The number of Most Visited Tile Placement experiment actions logged.
-  NUM_NTP_TILE_EXPERIMENT_ACTIONS
-};
-
-// Class for implementing the Most Visited Tile Placement experiment.
-class MostVisitedTilesExperiment {
- public:
-  // Helper method to shuffle MostVisited tiles for A/B testing purposes.
-  static void MaybeShuffle(MostVisitedURLList* data);
-
-  // Returns true if this user is part of the Most Visited Tile Placement
-  // experiment group where URLs currently open in another browser tab are not
-  // displayed on an NTP tile. Note: the experiment targets only the top-level
-  // of sites i.e. if www.foo.com/bar is open in browser, and www.foo.com is a
-  // recommended URL, www.foo.com will still appear on the next NTP open. The
-  // experiment will not remove a URL if doing so would cause the number of Most
-  // Visited recommendations to drop below eight.
-  static bool IsDontShowOpenURLsEnabled();
-
-  // Removes URLs already open in browser, for 1993 clients, if part of
-  // experiment described for IsDontShowOpenURLsEnabled().
-  static void RemoveItemsMatchingOpenTabs(
-      const std::set<std::string>& open_urls,
-      std::vector<InstantMostVisitedItem>* items);
-
-  // Removes URLs already open in browser, for non-1993 clients, if part of
-  // experiment described for IsDontShowOpenURLsEnabled().
-  static void RemovePageValuesMatchingOpenTabs(
-      const std::set<std::string>& open_urls,
-      base::ListValue* pages_value);
-
- private:
-  // Helper method to log the actions carried out by the Most Visited Tile
-  // Placement experiment.
-  static void LogInHistogram(NtpTileExperimentActions action);
-
-  // Helper method to determine whether |url| is in |open_urls|.
-  static bool ShouldRemoveURL(const std::set<std::string>& open_urls,
-                       const std::string& url,
-                       const size_t size);
-
-  DISALLOW_IMPLICIT_CONSTRUCTORS(MostVisitedTilesExperiment);
-};
-
-}  // namespace history
-
-#endif  // CHROME_BROWSER_HISTORY_MOST_VISITED_TILES_EXPERIMENT_H_