Move classes to //components/ntp_tiles.

chrome/browser/android/ntp/most_visited_sites.cc

Index: chrome/browser/android/ntp/most_visited_sites.cc
diff --git a/chrome/browser/android/ntp/most_visited_sites.cc b/chrome/browser/android/ntp/most_visited_sites.cc
deleted file mode 100644
index a8766c018233696536b596a16cb70d6046b9878f..0000000000000000000000000000000000000000
--- a/chrome/browser/android/ntp/most_visited_sites.cc
+++ /dev/null
@@ -1,757 +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/android/ntp/most_visited_sites.h"
-
-#include <utility>
-
-#include "base/callback.h"
-#include "base/command_line.h"
-#include "base/metrics/field_trial.h"
-#include "base/metrics/histogram.h"
-#include "base/metrics/sparse_histogram.h"
-#include "base/strings/string_number_conversions.h"
-#include "base/strings/string_util.h"
-#include "base/strings/stringprintf.h"
-#include "base/strings/utf_string_conversions.h"
-#include "base/time/time.h"
-#include "components/history/core/browser/top_sites.h"
-#include "components/ntp_tiles/pref_names.h"
-#include "components/ntp_tiles/switches.h"
-#include "components/pref_registry/pref_registry_syncable.h"
-#include "components/prefs/pref_service.h"
-#include "components/variations/variations_associated_data.h"
-#include "content/public/browser/browser_thread.h"
-#include "third_party/skia/include/core/SkBitmap.h"
-#include "ui/gfx/codec/jpeg_codec.h"
-#include "url/gurl.h"
-
-using content::BrowserThread;
-using history::TopSites;
-using suggestions::ChromeSuggestion;
-using suggestions::SuggestionsProfile;
-using suggestions::SuggestionsService;
-
-namespace {
-
-// Identifiers for the various tile sources.
-const char kHistogramClientName[] = "client";
-const char kHistogramServerName[] = "server";
-const char kHistogramServerFormat[] = "server%d";
-const char kHistogramPopularName[] = "popular";
-const char kHistogramWhitelistName[] = "whitelist";
-
-const char kPopularSitesFieldTrialName[] = "NTPPopularSites";
-
-// The visual type of a most visited tile.
-//
-// These values must stay in sync with the MostVisitedTileType enum
-// in histograms.xml.
-//
-// A Java counterpart will be generated for this enum.
-// GENERATED_JAVA_ENUM_PACKAGE: org.chromium.chrome.browser.ntp
-enum MostVisitedTileType {
-    // The icon or thumbnail hasn't loaded yet.
-    NONE,
-    // The item displays a site's actual favicon or touch icon.
-    ICON_REAL,
-    // The item displays a color derived from the site's favicon or touch icon.
-    ICON_COLOR,
-    // The item displays a default gray box in place of an icon.
-    ICON_DEFAULT,
-    NUM_TILE_TYPES,
-};
-
-std::unique_ptr<SkBitmap> MaybeFetchLocalThumbnail(
-    const GURL& url,
-    const scoped_refptr<TopSites>& top_sites) {
-  DCHECK_CURRENTLY_ON(BrowserThread::DB);
-  scoped_refptr<base::RefCountedMemory> image;
-  std::unique_ptr<SkBitmap> bitmap;
-  if (top_sites && top_sites->GetPageThumbnail(url, false, &image))
-    bitmap = gfx::JPEGCodec::Decode(image->front(), image->size());
-  return bitmap;
-}
-
-// 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);
-}
-
-bool ShouldShowPopularSites() {
-  // Note: It's important to query the field trial state first, to ensure that
-  // UMA reports the correct group.
-  const std::string group_name =
-      base::FieldTrialList::FindFullName(kPopularSitesFieldTrialName);
-  base::CommandLine* cmd_line = base::CommandLine::ForCurrentProcess();
-  if (cmd_line->HasSwitch(ntp_tiles::switches::kDisableNTPPopularSites))
-    return false;
-  if (cmd_line->HasSwitch(ntp_tiles::switches::kEnableNTPPopularSites))
-    return true;
-  return base::StartsWith(group_name, "Enabled",
-                          base::CompareCase::INSENSITIVE_ASCII);
-}
-
-std::string GetPopularSitesCountry() {
-  return variations::GetVariationParamValue(kPopularSitesFieldTrialName,
-                                            "country");
-}
-
-std::string GetPopularSitesVersion() {
-  return variations::GetVariationParamValue(kPopularSitesFieldTrialName,
-                                            "version");
-}
-
-// Determine whether we need any popular suggestions to fill up a grid of
-// |num_tiles| tiles.
-bool NeedPopularSites(const PrefService* prefs, size_t num_tiles) {
-  const base::ListValue* source_list =
-      prefs->GetList(ntp_tiles::prefs::kNTPSuggestionsIsPersonal);
-  // If there aren't enough previous suggestions to fill the grid, we need
-  // popular suggestions.
-  if (source_list->GetSize() < num_tiles)
-    return true;
-  // Otherwise, if any of the previous suggestions is not personal, then also
-  // get popular suggestions.
-  for (size_t i = 0; i < num_tiles; ++i) {
-    bool is_personal = false;
-    if (source_list->GetBoolean(i, &is_personal) && !is_personal)
-      return true;
-  }
-  // The whole grid is already filled with personal suggestions, no point in
-  // bothering with popular ones.
-  return false;
-}
-
-bool AreURLsEquivalent(const GURL& url1, const GURL& url2) {
-  return url1.host() == url2.host() && url1.path() == url2.path();
-}
-
-std::string GetSourceHistogramName(
-        const MostVisitedSites::Suggestion& suggestion) {
-  switch (suggestion.source) {
-    case MostVisitedSites::TOP_SITES:
-      return kHistogramClientName;
-    case MostVisitedSites::POPULAR:
-      return kHistogramPopularName;
-    case MostVisitedSites::WHITELIST:
-      return kHistogramWhitelistName;
-    case MostVisitedSites::SUGGESTIONS_SERVICE:
-      return suggestion.provider_index >= 0
-                 ? base::StringPrintf(kHistogramServerFormat,
-                                      suggestion.provider_index)
-                 : kHistogramServerName;
-  }
-  NOTREACHED();
-  return std::string();
-}
-
-}  // namespace
-
-MostVisitedSites::Suggestion::Suggestion() : provider_index(-1) {}
-
-MostVisitedSites::Suggestion::~Suggestion() {}
-
-MostVisitedSites::Suggestion::Suggestion(Suggestion&&) = default;
-MostVisitedSites::Suggestion&
-MostVisitedSites::Suggestion::operator=(Suggestion&&) = default;
-
-MostVisitedSites::MostVisitedSites(
-    PrefService* prefs,
-    const TemplateURLService* template_url_service,
-    variations::VariationsService* variations_service,
-    net::URLRequestContextGetter* download_context,
-    const base::FilePath& popular_sites_directory,
-    scoped_refptr<history::TopSites> top_sites,
-    SuggestionsService* suggestions,
-    MostVisitedSitesSupervisor* supervisor)
-    : prefs_(prefs),
-      template_url_service_(template_url_service),
-      variations_service_(variations_service),
-      download_context_(download_context),
-      popular_sites_directory_(popular_sites_directory),
-      top_sites_(top_sites),
-      suggestions_service_(suggestions),
-      supervisor_(supervisor),
-      observer_(nullptr),
-      num_sites_(0),
-      received_most_visited_sites_(false),
-      received_popular_sites_(false),
-      recorded_uma_(false),
-      scoped_observer_(this),
-      mv_source_(SUGGESTIONS_SERVICE),
-      weak_ptr_factory_(this) {
-  supervisor_->SetObserver(this);
-}
-
-MostVisitedSites::~MostVisitedSites() {
-  supervisor_->SetObserver(nullptr);
-}
-
-void MostVisitedSites::SetMostVisitedURLsObserver(
-      MostVisitedSites::Observer* observer, int num_sites) {
-  DCHECK(observer);
-  observer_ = observer;
-  num_sites_ = num_sites;
-
-  if (ShouldShowPopularSites() &&
-      NeedPopularSites(prefs_, num_sites_)) {
-    popular_sites_.reset(new PopularSites(
-        prefs_, template_url_service_, variations_service_, download_context_,
-        popular_sites_directory_, GetPopularSitesCountry(),
-        GetPopularSitesVersion(), false,
-        base::Bind(&MostVisitedSites::OnPopularSitesAvailable,
-                   base::Unretained(this))));
-  } else {
-    received_popular_sites_ = true;
-  }
-
-  if (top_sites_) {
-    // TopSites updates itself after a delay. To ensure up-to-date results,
-    // force an update now.
-    top_sites_->SyncWithHistory();
-
-    // Register as TopSitesObserver so that we can update ourselves when the
-    // TopSites changes.
-    scoped_observer_.Add(top_sites_.get());
-  }
-
-  suggestions_subscription_ = suggestions_service_->AddCallback(
-      base::Bind(&MostVisitedSites::OnSuggestionsProfileAvailable,
-                 base::Unretained(this)));
-
-  // Immediately build the current suggestions, getting personal suggestions
-  // from the SuggestionsService's cache or, if that is empty, from TopSites.
-  BuildCurrentSuggestions();
-  // Also start a request for fresh suggestions.
-  suggestions_service_->FetchSuggestionsData();
-}
-
-void MostVisitedSites::GetURLThumbnail(
-    const GURL& url,
-    const ThumbnailCallback& callback) {
-  DCHECK_CURRENTLY_ON(BrowserThread::UI);
-
-  BrowserThread::PostTaskAndReplyWithResult(
-      BrowserThread::DB, FROM_HERE,
-      base::Bind(&MaybeFetchLocalThumbnail, url, top_sites_),
-      base::Bind(&MostVisitedSites::OnLocalThumbnailFetched,
-                 weak_ptr_factory_.GetWeakPtr(), url, callback));
-}
-
-void MostVisitedSites::OnLocalThumbnailFetched(
-    const GURL& url,
-    const ThumbnailCallback& callback,
-    std::unique_ptr<SkBitmap> bitmap) {
-  DCHECK_CURRENTLY_ON(BrowserThread::UI);
-  if (!bitmap.get()) {
-    // A thumbnail is not locally available for |url|. Make sure it is put in
-    // the list to be fetched at the next visit to this site.
-    if (top_sites_)
-      top_sites_->AddForcedURL(url, base::Time::Now());
-    // Also fetch a remote thumbnail if possible. PopularSites or the
-    // SuggestionsService can supply a thumbnail download URL.
-    if (popular_sites_) {
-      const std::vector<PopularSites::Site>& sites = popular_sites_->sites();
-      auto it = std::find_if(
-          sites.begin(), sites.end(),
-          [&url](const PopularSites::Site& site) { return site.url == url; });
-      if (it != sites.end() && it->thumbnail_url.is_valid()) {
-        return suggestions_service_->GetPageThumbnailWithURL(
-            url, it->thumbnail_url,
-            base::Bind(&MostVisitedSites::OnObtainedThumbnail,
-                       weak_ptr_factory_.GetWeakPtr(), false, callback));
-      }
-    }
-    if (mv_source_ == SUGGESTIONS_SERVICE) {
-      return suggestions_service_->GetPageThumbnail(
-          url, base::Bind(&MostVisitedSites::OnObtainedThumbnail,
-                          weak_ptr_factory_.GetWeakPtr(), false, callback));
-    }
-  }
-  OnObtainedThumbnail(true, callback, url, bitmap.get());
-}
-
-void MostVisitedSites::OnObtainedThumbnail(
-    bool is_local_thumbnail,
-    const ThumbnailCallback& callback,
-    const GURL& url,
-    const SkBitmap* bitmap) {
-  DCHECK_CURRENTLY_ON(BrowserThread::UI);
-  callback.Run(is_local_thumbnail, bitmap);
-}
-
-void MostVisitedSites::AddOrRemoveBlacklistedUrl(
-    const GURL& url, bool add_url) {
-  // Always blacklist in the local TopSites.
-  if (top_sites_) {
-    if (add_url)
-      top_sites_->AddBlacklistedURL(url);
-    else
-      top_sites_->RemoveBlacklistedURL(url);
-  }
-
-  // Only blacklist in the server-side suggestions service if it's active.
-  if (mv_source_ == SUGGESTIONS_SERVICE) {
-    if (add_url)
-      suggestions_service_->BlacklistURL(url);
-    else
-      suggestions_service_->UndoBlacklistURL(url);
-  }
-}
-
-void MostVisitedSites::RecordTileTypeMetrics(
-    const std::vector<int>& tile_types) {
-  DCHECK_EQ(current_suggestions_.size(), tile_types.size());
-  int counts_per_type[NUM_TILE_TYPES] = {0};
-  for (size_t i = 0; i < tile_types.size(); ++i) {
-    int tile_type = tile_types[i];
-    ++counts_per_type[tile_type];
-    std::string histogram = base::StringPrintf(
-        "NewTabPage.TileType.%s",
-        GetSourceHistogramName(current_suggestions_[i]).c_str());
-    LogHistogramEvent(histogram, tile_type, NUM_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 MostVisitedSites::RecordOpenedMostVisitedItem(int index, int tile_type) {
-  DCHECK_GE(index, 0);
-  DCHECK_LT(index, static_cast<int>(current_suggestions_.size()));
-  std::string histogram = base::StringPrintf(
-      "NewTabPage.MostVisited.%s",
-      GetSourceHistogramName(current_suggestions_[index]).c_str());
-  LogHistogramEvent(histogram, index, num_sites_);
-
-  histogram = base::StringPrintf(
-      "NewTabPage.TileTypeClicked.%s",
-      GetSourceHistogramName(current_suggestions_[index]).c_str());
-  LogHistogramEvent(histogram, tile_type, NUM_TILE_TYPES);
-}
-
-void MostVisitedSites::OnBlockedSitesChanged() {
-  BuildCurrentSuggestions();
-}
-
-// static
-void MostVisitedSites::RegisterProfilePrefs(
-    user_prefs::PrefRegistrySyncable* registry) {
-  registry->RegisterListPref(ntp_tiles::prefs::kNTPSuggestionsURL);
-  registry->RegisterListPref(ntp_tiles::prefs::kNTPSuggestionsIsPersonal);
-}
-
-void MostVisitedSites::BuildCurrentSuggestions() {
-  // Get the current suggestions from cache. If the cache is empty, this will
-  // fall back to TopSites.
-  OnSuggestionsProfileAvailable(
-      suggestions_service_->GetSuggestionsDataFromCache());
-}
-
-void MostVisitedSites::InitiateTopSitesQuery() {
-  if (!top_sites_)
-    return;
-
-  top_sites_->GetMostVisitedURLs(
-      base::Bind(&MostVisitedSites::OnMostVisitedURLsAvailable,
-                 weak_ptr_factory_.GetWeakPtr()),
-      false);
-}
-
-base::FilePath MostVisitedSites::GetWhitelistLargeIconPath(const GURL& url) {
-  for (const auto& whitelist : supervisor_->whitelists()) {
-    if (AreURLsEquivalent(whitelist.entry_point, url))
-      return whitelist.large_icon_path;
-  }
-  return base::FilePath();
-}
-
-void MostVisitedSites::OnMostVisitedURLsAvailable(
-    const history::MostVisitedURLList& visited_list) {
-  MostVisitedSites::SuggestionsPtrVector suggestions;
-  size_t num_tiles =
-      std::min(visited_list.size(), static_cast<size_t>(num_sites_));
-  for (size_t i = 0; i < num_tiles; ++i) {
-    const history::MostVisitedURL& visited = visited_list[i];
-    if (visited.url.is_empty()) {
-      num_tiles = i;
-      break;  // This is the signal that there are no more real visited sites.
-    }
-    if (supervisor_->IsBlocked(visited.url))
-      continue;
-
-    std::unique_ptr<Suggestion> suggestion(new Suggestion());
-    suggestion->title = visited.title;
-    suggestion->url = visited.url;
-    suggestion->source = TOP_SITES;
-    suggestion->whitelist_icon_path = GetWhitelistLargeIconPath(visited.url);
-
-    suggestions.push_back(std::move(suggestion));
-  }
-
-  received_most_visited_sites_ = true;
-  mv_source_ = TOP_SITES;
-  SaveNewNTPSuggestions(&suggestions);
-  NotifyMostVisitedURLsObserver();
-}
-
-void MostVisitedSites::OnSuggestionsProfileAvailable(
-    const SuggestionsProfile& suggestions_profile) {
-  int num_tiles = suggestions_profile.suggestions_size();
-  // With no server suggestions, fall back to local TopSites.
-  if (num_tiles == 0) {
-    InitiateTopSitesQuery();
-    return;
-  }
-  if (num_sites_ < num_tiles)
-    num_tiles = num_sites_;
-
-  MostVisitedSites::SuggestionsPtrVector suggestions;
-  for (int i = 0; i < num_tiles; ++i) {
-    const ChromeSuggestion& suggestion = suggestions_profile.suggestions(i);
-    if (supervisor_->IsBlocked(GURL(suggestion.url())))
-      continue;
-
-    std::unique_ptr<Suggestion> generated_suggestion(new Suggestion());
-    generated_suggestion->title = base::UTF8ToUTF16(suggestion.title());
-    generated_suggestion->url = GURL(suggestion.url());
-    generated_suggestion->source = SUGGESTIONS_SERVICE;
-    generated_suggestion->whitelist_icon_path = GetWhitelistLargeIconPath(
-        GURL(suggestion.url()));
-    if (suggestion.providers_size() > 0)
-      generated_suggestion->provider_index = suggestion.providers(0);
-
-    suggestions.push_back(std::move(generated_suggestion));
-  }
-
-  received_most_visited_sites_ = true;
-  mv_source_ = SUGGESTIONS_SERVICE;
-  SaveNewNTPSuggestions(&suggestions);
-  NotifyMostVisitedURLsObserver();
-}
-
-MostVisitedSites::SuggestionsPtrVector
-MostVisitedSites::CreateWhitelistEntryPointSuggestions(
-    const MostVisitedSites::SuggestionsPtrVector& personal_suggestions) {
-  size_t num_personal_suggestions = personal_suggestions.size();
-  DCHECK_LE(num_personal_suggestions, static_cast<size_t>(num_sites_));
-
-  size_t num_whitelist_suggestions = num_sites_ - num_personal_suggestions;
-  MostVisitedSites::SuggestionsPtrVector whitelist_suggestions;
-
-  std::set<std::string> personal_hosts;
-  for (const auto& suggestion : personal_suggestions)
-    personal_hosts.insert(suggestion->url.host());
-
-  for (const auto& whitelist : supervisor_->whitelists()) {
-    // Skip blacklisted sites.
-    if (top_sites_ && top_sites_->IsBlacklisted(whitelist.entry_point))
-      continue;
-
-    // Skip suggestions already present.
-    if (personal_hosts.find(whitelist.entry_point.host()) !=
-        personal_hosts.end())
-      continue;
-
-    // Skip whitelist entry points that are manually blocked.
-    if (supervisor_->IsBlocked(whitelist.entry_point))
-      continue;
-
-    std::unique_ptr<Suggestion> suggestion(new Suggestion());
-    suggestion->title = whitelist.title;
-    suggestion->url = whitelist.entry_point;
-    suggestion->source = WHITELIST;
-    suggestion->whitelist_icon_path = whitelist.large_icon_path;
-
-    whitelist_suggestions.push_back(std::move(suggestion));
-    if (whitelist_suggestions.size() >= num_whitelist_suggestions)
-      break;
-  }
-
-  return whitelist_suggestions;
-}
-
-MostVisitedSites::SuggestionsPtrVector
-MostVisitedSites::CreatePopularSitesSuggestions(
-    const MostVisitedSites::SuggestionsPtrVector& personal_suggestions,
-    const MostVisitedSites::SuggestionsPtrVector& whitelist_suggestions) {
-  // For child accounts popular sites suggestions will not be added.
-  if (supervisor_->IsChildProfile())
-    return MostVisitedSites::SuggestionsPtrVector();
-
-  size_t num_suggestions =
-      personal_suggestions.size() + whitelist_suggestions.size();
-  DCHECK_LE(num_suggestions, static_cast<size_t>(num_sites_));
-
-  // Collect non-blacklisted popular suggestions, skipping those already present
-  // in the personal suggestions.
-  size_t num_popular_sites_suggestions = num_sites_ - num_suggestions;
-  MostVisitedSites::SuggestionsPtrVector popular_sites_suggestions;
-
-  if (num_popular_sites_suggestions > 0 && popular_sites_) {
-    std::set<std::string> hosts;
-    for (const auto& suggestion : personal_suggestions)
-      hosts.insert(suggestion->url.host());
-    for (const auto& suggestion : whitelist_suggestions)
-      hosts.insert(suggestion->url.host());
-    for (const PopularSites::Site& popular_site : popular_sites_->sites()) {
-      // Skip blacklisted sites.
-      if (top_sites_ && top_sites_->IsBlacklisted(popular_site.url))
-        continue;
-      std::string host = popular_site.url.host();
-      // Skip suggestions already present in personal or whitelists.
-      if (hosts.find(host) != hosts.end())
-        continue;
-
-      std::unique_ptr<Suggestion> suggestion(new Suggestion());
-      suggestion->title = popular_site.title;
-      suggestion->url = GURL(popular_site.url);
-      suggestion->source = POPULAR;
-
-      popular_sites_suggestions.push_back(std::move(suggestion));
-      if (popular_sites_suggestions.size() >= num_popular_sites_suggestions)
-        break;
-    }
-  }
-  return popular_sites_suggestions;
-}
-
-void MostVisitedSites::SaveNewNTPSuggestions(
-    MostVisitedSites::SuggestionsPtrVector* personal_suggestions) {
-  MostVisitedSites::SuggestionsPtrVector whitelist_suggestions =
-      CreateWhitelistEntryPointSuggestions(*personal_suggestions);
-  MostVisitedSites::SuggestionsPtrVector popular_sites_suggestions =
-      CreatePopularSitesSuggestions(*personal_suggestions,
-                                    whitelist_suggestions);
-  size_t num_actual_tiles = personal_suggestions->size() +
-                            whitelist_suggestions.size() +
-                            popular_sites_suggestions.size();
-  std::vector<std::string> old_sites_url;
-  std::vector<bool> old_sites_is_personal;
-  // TODO(treib): We used to call |GetPreviousNTPSites| here to populate
-  // |old_sites_url| and |old_sites_is_personal|, but that caused problems
-  // (crbug.com/585391). Either figure out a way to fix them and re-enable,
-  // or properly remove the order-persisting code. crbug.com/601734
-  MostVisitedSites::SuggestionsPtrVector merged_suggestions = MergeSuggestions(
-      personal_suggestions, &whitelist_suggestions, &popular_sites_suggestions,
-      old_sites_url, old_sites_is_personal);
-  DCHECK_EQ(num_actual_tiles, merged_suggestions.size());
-  current_suggestions_.resize(merged_suggestions.size());
-  for (size_t i = 0; i < merged_suggestions.size(); ++i)
-    std::swap(*merged_suggestions[i], current_suggestions_[i]);
-  if (received_popular_sites_)
-    SaveCurrentNTPSites();
-}
-
-// static
-MostVisitedSites::SuggestionsPtrVector MostVisitedSites::MergeSuggestions(
-    MostVisitedSites::SuggestionsPtrVector* personal_suggestions,
-    MostVisitedSites::SuggestionsPtrVector* whitelist_suggestions,
-    MostVisitedSites::SuggestionsPtrVector* popular_suggestions,
-    const std::vector<std::string>& old_sites_url,
-    const std::vector<bool>& old_sites_is_personal) {
-  size_t num_personal_suggestions = personal_suggestions->size();
-  size_t num_whitelist_suggestions = whitelist_suggestions->size();
-  size_t num_popular_suggestions = popular_suggestions->size();
-  size_t num_tiles = num_popular_suggestions + num_whitelist_suggestions +
-                     num_personal_suggestions;
-  MostVisitedSites::SuggestionsPtrVector merged_suggestions;
-  merged_suggestions.resize(num_tiles);
-
-  size_t num_old_tiles = old_sites_url.size();
-  DCHECK_LE(num_old_tiles, num_tiles);
-  DCHECK_EQ(num_old_tiles, old_sites_is_personal.size());
-  std::vector<std::string> old_sites_host;
-  old_sites_host.reserve(num_old_tiles);
-  // Only populate the hosts for popular suggestions as only they can be
-  // replaced by host. Personal suggestions require an exact url match to be
-  // replaced.
-  for (size_t i = 0; i < num_old_tiles; ++i) {
-    old_sites_host.push_back(old_sites_is_personal[i]
-                                 ? std::string()
-                                 : GURL(old_sites_url[i]).host());
-  }
-
-  // Insert personal suggestions if they existed previously.
-  std::vector<size_t> new_personal_suggestions = InsertMatchingSuggestions(
-      personal_suggestions, &merged_suggestions, old_sites_url, old_sites_host);
-  // Insert whitelist suggestions if they existed previously.
-  std::vector<size_t> new_whitelist_suggestions =
-      InsertMatchingSuggestions(whitelist_suggestions, &merged_suggestions,
-                                old_sites_url, old_sites_host);
-  // Insert popular suggestions if they existed previously.
-  std::vector<size_t> new_popular_suggestions = InsertMatchingSuggestions(
-      popular_suggestions, &merged_suggestions, old_sites_url, old_sites_host);
-  // Insert leftover personal suggestions.
-  size_t filled_so_far = InsertAllSuggestions(
-      0, new_personal_suggestions, personal_suggestions, &merged_suggestions);
-  // Insert leftover whitelist suggestions.
-  filled_so_far =
-      InsertAllSuggestions(filled_so_far, new_whitelist_suggestions,
-                           whitelist_suggestions, &merged_suggestions);
-  // Insert leftover popular suggestions.
-  InsertAllSuggestions(filled_so_far, new_popular_suggestions,
-                       popular_suggestions, &merged_suggestions);
-  return merged_suggestions;
-}
-
-void MostVisitedSites::GetPreviousNTPSites(
-    size_t num_tiles,
-    std::vector<std::string>* old_sites_url,
-    std::vector<bool>* old_sites_is_personal) const {
-  const base::ListValue* url_list = prefs_->GetList(
-      ntp_tiles::prefs::kNTPSuggestionsURL);
-  const base::ListValue* source_list =
-      prefs_->GetList(ntp_tiles::prefs::kNTPSuggestionsIsPersonal);
-  DCHECK_EQ(url_list->GetSize(), source_list->GetSize());
-  if (url_list->GetSize() < num_tiles)
-    num_tiles = url_list->GetSize();
-  if (num_tiles == 0) {
-    // No fallback required as Personal suggestions take precedence anyway.
-    return;
-  }
-  old_sites_url->reserve(num_tiles);
-  old_sites_is_personal->reserve(num_tiles);
-  for (size_t i = 0; i < num_tiles; ++i) {
-    std::string url_string;
-    bool success = url_list->GetString(i, &url_string);
-    DCHECK(success);
-    old_sites_url->push_back(url_string);
-    bool is_personal;
-    success = source_list->GetBoolean(i, &is_personal);
-    DCHECK(success);
-    old_sites_is_personal->push_back(is_personal);
-  }
-}
-
-void MostVisitedSites::SaveCurrentNTPSites() {
-  base::ListValue url_list;
-  base::ListValue source_list;
-  for (const auto& suggestion : current_suggestions_) {
-    url_list.AppendString(suggestion.url.spec());
-    source_list.AppendBoolean(suggestion.source != MostVisitedSites::POPULAR);
-  }
-  prefs_->Set(ntp_tiles::prefs::kNTPSuggestionsIsPersonal, source_list);
-  prefs_->Set(ntp_tiles::prefs::kNTPSuggestionsURL, url_list);
-}
-
-// static
-std::vector<size_t> MostVisitedSites::InsertMatchingSuggestions(
-    MostVisitedSites::SuggestionsPtrVector* src_suggestions,
-    MostVisitedSites::SuggestionsPtrVector* dst_suggestions,
-    const std::vector<std::string>& match_urls,
-    const std::vector<std::string>& match_hosts) {
-  std::vector<size_t> unmatched_suggestions;
-  size_t num_src_suggestions = src_suggestions->size();
-  size_t num_matchers = match_urls.size();
-  for (size_t i = 0; i < num_src_suggestions; ++i) {
-    size_t position;
-    for (position = 0; position < num_matchers; ++position) {
-      if ((*dst_suggestions)[position] != nullptr)
-        continue;
-      if (match_urls[position] == (*src_suggestions)[i]->url.spec())
-        break;
-      // match_hosts is only populated for suggestions which can be replaced by
-      // host matching like popular suggestions.
-      if (match_hosts[position] == (*src_suggestions)[i]->url.host())
-        break;
-    }
-    if (position == num_matchers) {
-      unmatched_suggestions.push_back(i);
-    } else {
-      // A move is required as the source and destination containers own the
-      // elements.
-      std::swap((*dst_suggestions)[position], (*src_suggestions)[i]);
-    }
-  }
-  return unmatched_suggestions;
-}
-
-// static
-size_t MostVisitedSites::InsertAllSuggestions(
-    size_t start_position,
-    const std::vector<size_t>& insert_positions,
-    std::vector<std::unique_ptr<Suggestion>>* src_suggestions,
-    std::vector<std::unique_ptr<Suggestion>>* dst_suggestions) {
-  size_t num_inserts = insert_positions.size();
-  size_t num_dests = dst_suggestions->size();
-
-  size_t src_pos = 0;
-  size_t i = start_position;
-  for (; i < num_dests && src_pos < num_inserts; ++i) {
-    if ((*dst_suggestions)[i] != nullptr)
-      continue;
-    size_t src = insert_positions[src_pos++];
-    std::swap((*dst_suggestions)[i], (*src_suggestions)[src]);
-  }
-  // Return destination positions filled so far which becomes the start_position
-  // for future runs.
-  return i;
-}
-
-void MostVisitedSites::NotifyMostVisitedURLsObserver() {
-  size_t num_suggestions = current_suggestions_.size();
-  if (received_most_visited_sites_ && received_popular_sites_ &&
-      !recorded_uma_) {
-    RecordImpressionUMAMetrics();
-    UMA_HISTOGRAM_SPARSE_SLOWLY("NewTabPage.NumberOfTiles", num_suggestions);
-    recorded_uma_ = true;
-  }
-
-  if (!observer_)
-    return;
-
-  observer_->OnMostVisitedURLsAvailable(current_suggestions_);
-}
-
-void MostVisitedSites::OnPopularSitesAvailable(bool success) {
-  received_popular_sites_ = true;
-
-  if (!success) {
-    LOG(WARNING) << "Download of popular sites failed";
-    return;
-  }
-
-  // Pass the popular sites to the observer. This will cause it to fetch any
-  // missing icons, but will *not* cause it to display the popular sites.
-  observer_->OnPopularURLsAvailable(popular_sites_->sites());
-
-  // Re-build the suggestions list. Once done, this will notify the observer.
-  BuildCurrentSuggestions();
-}
-
-void MostVisitedSites::RecordImpressionUMAMetrics() {
-  for (size_t i = 0; i < current_suggestions_.size(); i++) {
-    std::string histogram = base::StringPrintf(
-        "NewTabPage.SuggestionsImpression.%s",
-        GetSourceHistogramName(current_suggestions_[i]).c_str());
-    LogHistogramEvent(histogram, static_cast<int>(i), num_sites_);
-  }
-}
-
-void MostVisitedSites::TopSitesLoaded(TopSites* top_sites) {}
-
-void MostVisitedSites::TopSitesChanged(TopSites* top_sites,
-                                       ChangeReason change_reason) {
-  if (mv_source_ == TOP_SITES) {
-    // The displayed suggestions are invalidated.
-    InitiateTopSitesQuery();
-  }
-}