Splits the OfflinePageModel into and interface and and implementation class.

components/offline_pages/offline_page_model.cc

Index: components/offline_pages/offline_page_model.cc
diff --git a/components/offline_pages/offline_page_model.cc b/components/offline_pages/offline_page_model.cc
index beb622cafba81da6ccb0c704dd381c956dde9c9b..2ce7d1ac680001c0421157da913e242f703db23b 100644
--- a/components/offline_pages/offline_page_model.cc
+++ b/components/offline_pages/offline_page_model.cc
@@ -4,860 +4,17 @@
 
 #include "components/offline_pages/offline_page_model.h"
 
-#include <algorithm>
-#include <utility>
-
-#include "base/bind.h"
-#include "base/files/file_util.h"
-#include "base/location.h"
-#include "base/logging.h"
-#include "base/metrics/histogram_macros.h"
-#include "base/optional.h"
-#include "base/rand_util.h"
-#include "base/sequenced_task_runner.h"
-#include "base/strings/string_number_conversions.h"
-#include "base/threading/thread_task_runner_handle.h"
-#include "base/time/time.h"
-#include "components/offline_pages/archive_manager.h"
-#include "components/offline_pages/client_policy_controller.h"
-#include "components/offline_pages/offline_page_item.h"
-#include "components/offline_pages/offline_page_storage_manager.h"
 #include "url/gurl.h"
 
-using ArchiverResult = offline_pages::OfflinePageArchiver::ArchiverResult;
-
 namespace offline_pages {
 
-namespace {
-
-// This enum is used in an UMA histogram. Hence the entries here shouldn't
-// be deleted or re-ordered and new ones should be added to the end.
-enum ClearAllStatus {
-  CLEAR_ALL_SUCCEEDED,
-  STORE_RESET_FAILED,
-  STORE_RELOAD_FAILED,
-
-  // NOTE: always keep this entry at the end.
-  CLEAR_ALL_STATUS_COUNT
-};
-
-// The maximum histogram size for the metrics that measure time between views of
-// a given page.
-const base::TimeDelta kMaxOpenedPageHistogramBucket =
-    base::TimeDelta::FromDays(90);
-
-SavePageResult ToSavePageResult(ArchiverResult archiver_result) {
-  SavePageResult result;
-  switch (archiver_result) {
-    case ArchiverResult::SUCCESSFULLY_CREATED:
-      result = SavePageResult::SUCCESS;
-      break;
-    case ArchiverResult::ERROR_DEVICE_FULL:
-      result = SavePageResult::DEVICE_FULL;
-      break;
-    case ArchiverResult::ERROR_CONTENT_UNAVAILABLE:
-      result = SavePageResult::CONTENT_UNAVAILABLE;
-      break;
-    case ArchiverResult::ERROR_ARCHIVE_CREATION_FAILED:
-      result = SavePageResult::ARCHIVE_CREATION_FAILED;
-      break;
-    case ArchiverResult::ERROR_CANCELED:
-      result = SavePageResult::CANCELLED;
-      break;
-    case ArchiverResult::ERROR_SECURITY_CERTIFICATE:
-      result = SavePageResult::SECURITY_CERTIFICATE_ERROR;
-      break;
-    default:
-      NOTREACHED();
-      result = SavePageResult::CONTENT_UNAVAILABLE;
-  }
-  return result;
-}
-
-std::string AddHistogramSuffix(const ClientId& client_id,
-                               const char* histogram_name) {
-  if (client_id.name_space.empty()) {
-    NOTREACHED();
-    return histogram_name;
-  }
-  std::string adjusted_histogram_name(histogram_name);
-  adjusted_histogram_name += ".";
-  adjusted_histogram_name += client_id.name_space;
-  return adjusted_histogram_name;
-}
-
-void ReportStorageHistogramsAfterSave(
-    const ArchiveManager::StorageStats& storage_stats) {
-  const int kMB = 1024 * 1024;
-  int free_disk_space_mb =
-      static_cast<int>(storage_stats.free_disk_space / kMB);
-  UMA_HISTOGRAM_CUSTOM_COUNTS("OfflinePages.SavePage.FreeSpaceMB",
-                              free_disk_space_mb, 1, 500000, 50);
-
-  int total_page_size_mb =
-      static_cast<int>(storage_stats.total_archives_size / kMB);
-  UMA_HISTOGRAM_COUNTS_10000("OfflinePages.TotalPageSize", total_page_size_mb);
-}
-
-void ReportStorageHistogramsAfterDelete(
-    const ArchiveManager::StorageStats& storage_stats) {
-  const int kMB = 1024 * 1024;
-  int free_disk_space_mb =
-      static_cast<int>(storage_stats.free_disk_space / kMB);
-  UMA_HISTOGRAM_CUSTOM_COUNTS("OfflinePages.DeletePage.FreeSpaceMB",
-                              free_disk_space_mb, 1, 500000, 50);
-
-  int total_page_size_mb =
-      static_cast<int>(storage_stats.total_archives_size / kMB);
-  UMA_HISTOGRAM_COUNTS_10000("OfflinePages.TotalPageSize", total_page_size_mb);
-
-  if (storage_stats.free_disk_space > 0) {
-    int percentage_of_free = static_cast<int>(
-        1.0 * storage_stats.total_archives_size /
-        (storage_stats.total_archives_size + storage_stats.free_disk_space) *
-        100);
-    UMA_HISTOGRAM_PERCENTAGE(
-        "OfflinePages.DeletePage.TotalPageSizeAsPercentageOfFreeSpace",
-        percentage_of_free);
-  }
-}
-
-}  // namespace
-
 // static
 bool OfflinePageModel::CanSavePage(const GURL& url) {
   return url.SchemeIsHTTPOrHTTPS();
 }
 
-// protected
-OfflinePageModel::OfflinePageModel()
-    : is_loaded_(false), weak_ptr_factory_(this) {}
-
-OfflinePageModel::OfflinePageModel(
-    std::unique_ptr<OfflinePageMetadataStore> store,
-    const base::FilePath& archives_dir,
-    const scoped_refptr<base::SequencedTaskRunner>& task_runner)
-    : store_(std::move(store)),
-      archives_dir_(archives_dir),
-      is_loaded_(false),
-      policy_controller_(new ClientPolicyController()),
-      archive_manager_(new ArchiveManager(archives_dir, task_runner)),
-      weak_ptr_factory_(this) {
-  archive_manager_->EnsureArchivesDirCreated(
-      base::Bind(&OfflinePageModel::OnEnsureArchivesDirCreatedDone,
-                 weak_ptr_factory_.GetWeakPtr(), base::TimeTicks::Now()));
-}
-
-OfflinePageModel::~OfflinePageModel() {
-}
-
-void OfflinePageModel::AddObserver(Observer* observer) {
-  observers_.AddObserver(observer);
-}
-
-void OfflinePageModel::RemoveObserver(Observer* observer) {
-  observers_.RemoveObserver(observer);
-}
-
-void OfflinePageModel::SavePage(const GURL& url,
-                                const ClientId& client_id,
-                                std::unique_ptr<OfflinePageArchiver> archiver,
-                                const SavePageCallback& callback) {
-  DCHECK(is_loaded_);
-
-  // Skip saving the page that is not intended to be saved, like local file
-  // page.
-  if (url.is_valid() && !CanSavePage(url)) {
-    InformSavePageDone(callback, SavePageResult::SKIPPED, client_id,
-                       kInvalidOfflineId);
-    return;
-  }
-
-  // The web contents is not available if archiver is not created and passed.
-  if (!archiver.get()) {
-    InformSavePageDone(callback, SavePageResult::CONTENT_UNAVAILABLE, client_id,
-                       kInvalidOfflineId);
-    return;
-  }
-
-  int64_t offline_id = GenerateOfflineId();
-
-  archiver->CreateArchive(
-      archives_dir_,
-      offline_id,
-      base::Bind(&OfflinePageModel::OnCreateArchiveDone,
-                 weak_ptr_factory_.GetWeakPtr(), url, offline_id,
-                 client_id, base::Time::Now(), callback));
-  pending_archivers_.push_back(std::move(archiver));
-}
-
-void OfflinePageModel::MarkPageAccessed(int64_t offline_id) {
-  DCHECK(is_loaded_);
-  auto iter = offline_pages_.find(offline_id);
-  if (iter == offline_pages_.end())
-    return;
-
-  // Make a copy of the cached item and update it. The cached item should only
-  // be updated upon the successful store operation.
-  OfflinePageItem offline_page_item = iter->second;
-
-  base::Time now = base::Time::Now();
-  base::TimeDelta time_since_last_accessed =
-      now - offline_page_item.last_access_time;
-
-  // When the access account is still zero, the page is opened for the first
-  // time since its creation.
-  UMA_HISTOGRAM_CUSTOM_COUNTS(
-      AddHistogramSuffix(
-          offline_page_item.client_id,
-          (offline_page_item.access_count == 0) ?
-              "OfflinePages.FirstOpenSinceCreated" :
-              "OfflinePages.OpenSinceLastOpen").c_str(),
-      time_since_last_accessed.InMinutes(), 1,
-      kMaxOpenedPageHistogramBucket.InMinutes(), 50);
-
-  offline_page_item.last_access_time = now;
-  offline_page_item.access_count++;
-
-  store_->AddOrUpdateOfflinePage(
-      offline_page_item,
-      base::Bind(&OfflinePageModel::OnMarkPageAccesseDone,
-                 weak_ptr_factory_.GetWeakPtr(), offline_page_item));
-}
-
-void OfflinePageModel::DeletePagesByOfflineId(
-    const std::vector<int64_t>& offline_ids,
-    const DeletePageCallback& callback) {
-  if (!is_loaded_) {
-    delayed_tasks_.push_back(
-        base::Bind(&OfflinePageModel::DoDeletePagesByOfflineId,
-                   weak_ptr_factory_.GetWeakPtr(), offline_ids, callback));
-
-    return;
-  }
-  DoDeletePagesByOfflineId(offline_ids, callback);
-}
-
-void OfflinePageModel::DoDeletePagesByOfflineId(
-    const std::vector<int64_t>& offline_ids,
-    const DeletePageCallback& callback) {
-  DCHECK(is_loaded_);
-
-  std::vector<base::FilePath> paths_to_delete;
-  for (const auto& offline_id : offline_ids) {
-    auto iter = offline_pages_.find(offline_id);
-    if (iter != offline_pages_.end()) {
-      paths_to_delete.push_back(iter->second.file_path);
-    }
-  }
-
-  if (paths_to_delete.empty()) {
-    InformDeletePageDone(callback, DeletePageResult::NOT_FOUND);
-    return;
-  }
-
-  archive_manager_->DeleteMultipleArchives(
-      paths_to_delete,
-      base::Bind(&OfflinePageModel::OnDeleteArchiveFilesDone,
-                 weak_ptr_factory_.GetWeakPtr(), offline_ids, callback));
-}
-
-void OfflinePageModel::ClearAll(const base::Closure& callback) {
-  DCHECK(is_loaded_);
-
-  std::vector<int64_t> offline_ids;
-  for (const auto& id_page_pair : offline_pages_)
-    offline_ids.push_back(id_page_pair.first);
-  DeletePagesByOfflineId(
-      offline_ids,
-      base::Bind(&OfflinePageModel::OnRemoveAllFilesDoneForClearAll,
-                 weak_ptr_factory_.GetWeakPtr(), callback));
-}
-
-void OfflinePageModel::DeletePagesByURLPredicate(
-    const UrlPredicate& predicate,
-    const DeletePageCallback& callback) {
-  if (!is_loaded_) {
-    delayed_tasks_.push_back(
-        base::Bind(&OfflinePageModel::DoDeletePagesByURLPredicate,
-                   weak_ptr_factory_.GetWeakPtr(), predicate, callback));
-
-    return;
-  }
-  DoDeletePagesByURLPredicate(predicate, callback);
-}
-
-void OfflinePageModel::DoDeletePagesByURLPredicate(
-    const UrlPredicate& predicate,
-    const DeletePageCallback& callback) {
-  DCHECK(is_loaded_);
-
-  std::vector<int64_t> offline_ids;
-  for (const auto& id_page_pair : offline_pages_) {
-    if (predicate.Run(id_page_pair.second.url))
-      offline_ids.push_back(id_page_pair.first);
-  }
-  DoDeletePagesByOfflineId(offline_ids, callback);
-}
-
-void OfflinePageModel::HasPages(const std::string& name_space,
-                                const HasPagesCallback& callback) {
-  RunWhenLoaded(base::Bind(&OfflinePageModel::HasPagesAfterLoadDone,
-                           weak_ptr_factory_.GetWeakPtr(), name_space,
-                           callback));
-}
-
-void OfflinePageModel::HasPagesAfterLoadDone(
-    const std::string& name_space,
-    const HasPagesCallback& callback) const {
-  DCHECK(is_loaded_);
-
-  bool has_pages = false;
-
-  for (const auto& id_page_pair : offline_pages_) {
-    if (id_page_pair.second.client_id.name_space == name_space) {
-      has_pages = true;
-      break;
-    }
-  }
-
-  callback.Run(has_pages);
-}
-
-void OfflinePageModel::CheckPagesExistOffline(
-    const std::set<GURL>& urls,
-    const CheckPagesExistOfflineCallback& callback) {
-  RunWhenLoaded(
-      base::Bind(&OfflinePageModel::CheckPagesExistOfflineAfterLoadDone,
-                 weak_ptr_factory_.GetWeakPtr(), urls, callback));
-}
-
-void OfflinePageModel::CheckPagesExistOfflineAfterLoadDone(
-    const std::set<GURL>& urls,
-    const CheckPagesExistOfflineCallback& callback) {
-  DCHECK(is_loaded_);
-  CheckPagesExistOfflineResult result;
-  for (const auto& id_page_pair : offline_pages_) {
-    auto iter = urls.find(id_page_pair.second.url);
-    if (iter != urls.end())
-      result.insert(*iter);
-  }
-  callback.Run(result);
-}
-
-void OfflinePageModel::GetAllPages(
-    const MultipleOfflinePageItemCallback& callback) {
-  RunWhenLoaded(base::Bind(&OfflinePageModel::GetAllPagesAfterLoadDone,
-                           weak_ptr_factory_.GetWeakPtr(), callback));
-}
-
-void OfflinePageModel::GetAllPagesAfterLoadDone(
-    const MultipleOfflinePageItemCallback& callback) {
-  DCHECK(is_loaded_);
-
-  MultipleOfflinePageItemResult offline_pages;
-  for (const auto& id_page_pair : offline_pages_)
-    offline_pages.push_back(id_page_pair.second);
-
-  callback.Run(offline_pages);
-}
-
-void OfflinePageModel::GetOfflineIdsForClientId(
-    const ClientId& client_id,
-    const MultipleOfflineIdCallback& callback) {
-  RunWhenLoaded(
-      base::Bind(&OfflinePageModel::GetOfflineIdsForClientIdWhenLoadDone,
-                 weak_ptr_factory_.GetWeakPtr(), client_id, callback));
-}
-
-void OfflinePageModel::GetOfflineIdsForClientIdWhenLoadDone(
-    const ClientId& client_id,
-    const MultipleOfflineIdCallback& callback) const {
-  callback.Run(MaybeGetOfflineIdsForClientId(client_id));
-}
-
-const std::vector<int64_t> OfflinePageModel::MaybeGetOfflineIdsForClientId(
-    const ClientId& client_id) const {
-  DCHECK(is_loaded_);
-  std::vector<int64_t> results;
-
-  // We want only all pages, including those marked for deletion.
-  // TODO(bburns): actually use an index rather than linear scan.
-  for (const auto& id_page_pair : offline_pages_) {
-    if (id_page_pair.second.client_id == client_id)
-      results.push_back(id_page_pair.second.offline_id);
-  }
-  return results;
-}
-
-void OfflinePageModel::GetPageByOfflineId(
-    int64_t offline_id,
-    const SingleOfflinePageItemCallback& callback) {
-  RunWhenLoaded(base::Bind(&OfflinePageModel::GetPageByOfflineIdWhenLoadDone,
-                           weak_ptr_factory_.GetWeakPtr(), offline_id,
-                           callback));
-}
-
-void OfflinePageModel::GetPageByOfflineIdWhenLoadDone(
-    int64_t offline_id,
-    const SingleOfflinePageItemCallback& callback) const {
-  SingleOfflinePageItemResult result;
-  const OfflinePageItem* match = MaybeGetPageByOfflineId(offline_id);
-  if (match != nullptr)
-    result = *match;
-  callback.Run(result);
-}
-
-const OfflinePageItem* OfflinePageModel::MaybeGetPageByOfflineId(
-    int64_t offline_id) const {
-  const auto iter = offline_pages_.find(offline_id);
-  return iter != offline_pages_.end() ? &(iter->second) : nullptr;
-}
-
-void OfflinePageModel::GetPageByOfflineURL(
-    const GURL& offline_url,
-    const SingleOfflinePageItemCallback& callback) {
-  RunWhenLoaded(base::Bind(&OfflinePageModel::GetPageByOfflineURLWhenLoadDone,
-                           weak_ptr_factory_.GetWeakPtr(), offline_url,
-                           callback));
-}
-
-void OfflinePageModel::GetPageByOfflineURLWhenLoadDone(
-    const GURL& offline_url,
-    const SingleOfflinePageItemCallback& callback) const {
-  base::Optional<OfflinePageItem> result;
+OfflinePageModel::OfflinePageModel() {}
 
-  for (const auto& id_page_pair : offline_pages_) {
-    if (id_page_pair.second.GetOfflineURL() == offline_url) {
-      callback.Run(base::make_optional(id_page_pair.second));
-      return;
-    }
-  }
-
-  callback.Run(base::nullopt);
-}
-
-const OfflinePageItem* OfflinePageModel::MaybeGetPageByOfflineURL(
-    const GURL& offline_url) const {
-  for (const auto& id_page_pair : offline_pages_) {
-    if (id_page_pair.second.GetOfflineURL() == offline_url)
-      return &(id_page_pair.second);
-  }
-  return nullptr;
-}
-
-void OfflinePageModel::GetBestPageForOnlineURL(
-    const GURL& online_url,
-    const SingleOfflinePageItemCallback callback) {
-  RunWhenLoaded(
-      base::Bind(&OfflinePageModel::GetBestPageForOnlineURLWhenLoadDone,
-                 weak_ptr_factory_.GetWeakPtr(), online_url, callback));
-}
-
-void OfflinePageModel::GetBestPageForOnlineURLWhenLoadDone(
-    const GURL& online_url,
-    const SingleOfflinePageItemCallback& callback) const {
-  SingleOfflinePageItemResult result;
-
-  const OfflinePageItem* best_page = MaybeGetBestPageForOnlineURL(online_url);
-  if (best_page != nullptr)
-    result = *best_page;
-
-  callback.Run(result);
-}
-
-void OfflinePageModel::GetPagesByOnlineURL(
-    const GURL& online_url,
-    const MultipleOfflinePageItemCallback& callback) {
-  RunWhenLoaded(base::Bind(&OfflinePageModel::GetPagesByOnlineURLWhenLoadDone,
-                           weak_ptr_factory_.GetWeakPtr(), online_url,
-                           callback));
-}
-
-void OfflinePageModel::GetPagesByOnlineURLWhenLoadDone(
-    const GURL& online_url,
-    const MultipleOfflinePageItemCallback& callback) const {
-  std::vector<OfflinePageItem> result;
-
-  for (const auto& id_page_pair : offline_pages_) {
-    if (id_page_pair.second.url == online_url)
-      result.push_back(id_page_pair.second);
-  }
-
-  callback.Run(result);
-}
-
-const OfflinePageItem* OfflinePageModel::MaybeGetBestPageForOnlineURL(
-    const GURL& online_url) const {
-  const OfflinePageItem* result = nullptr;
-  for (const auto& id_page_pair : offline_pages_) {
-    if (id_page_pair.second.url == online_url) {
-      if (!result || id_page_pair.second.creation_time > result->creation_time)
-        result = &(id_page_pair.second);
-    }
-  }
-  return result;
-}
-
-void OfflinePageModel::CheckForExternalFileDeletion() {
-  DCHECK(is_loaded_);
-
-  archive_manager_->GetAllArchives(
-      base::Bind(&OfflinePageModel::ScanForMissingArchiveFiles,
-                 weak_ptr_factory_.GetWeakPtr()));
-}
-
-void OfflinePageModel::ExpirePages(const std::vector<int64_t>& offline_ids,
-                                   const base::Time& expiration_time) {
-  for (int64_t offline_id : offline_ids) {
-    auto iter = offline_pages_.find(offline_id);
-    if (iter == offline_pages_.end())
-      continue;
-
-    OfflinePageItem offline_page = iter->second;
-    offline_page.expiration_time = expiration_time;
-
-    store_->AddOrUpdateOfflinePage(
-        offline_page, base::Bind(&OfflinePageModel::OnExpirePageDone,
-                                 weak_ptr_factory_.GetWeakPtr(), offline_id,
-                                 expiration_time));
-  }
-}
-
-void OfflinePageModel::OnExpirePageDone(int64_t offline_id,
-                                        const base::Time& expiration_time,
-                                        bool success) {
-  // TODO(romax): Report UMA about successful expiration.
-  if (success) {
-    auto iter = offline_pages_.find(offline_id);
-    if (iter != offline_pages_.end())
-      iter->second.expiration_time = expiration_time;
-  }
-}
-
-ClientPolicyController* OfflinePageModel::GetPolicyController() {
-  return policy_controller_.get();
-}
-
-OfflinePageMetadataStore* OfflinePageModel::GetStoreForTesting() {
-  return store_.get();
-}
-
-OfflinePageStorageManager* OfflinePageModel::GetStorageManager() {
-  return storage_manager_.get();
-}
-
-bool OfflinePageModel::is_loaded() const {
-  return is_loaded_;
-}
-
-void OfflinePageModel::OnCreateArchiveDone(const GURL& requested_url,
-                                           int64_t offline_id,
-                                           const ClientId& client_id,
-                                           const base::Time& start_time,
-                                           const SavePageCallback& callback,
-                                           OfflinePageArchiver* archiver,
-                                           ArchiverResult archiver_result,
-                                           const GURL& url,
-                                           const base::FilePath& file_path,
-                                           int64_t file_size) {
-  if (requested_url != url) {
-    DVLOG(1) << "Saved URL does not match requested URL.";
-    // TODO(fgorski): We have created an archive for a wrong URL. It should be
-    // deleted from here, once archiver has the right functionality.
-    InformSavePageDone(callback, SavePageResult::ARCHIVE_CREATION_FAILED,
-                       client_id, offline_id);
-    DeletePendingArchiver(archiver);
-    return;
-  }
-
-  if (archiver_result != ArchiverResult::SUCCESSFULLY_CREATED) {
-    SavePageResult result = ToSavePageResult(archiver_result);
-    InformSavePageDone(callback, result, client_id, offline_id);
-    DeletePendingArchiver(archiver);
-    return;
-  }
-  OfflinePageItem offline_page_item(url, offline_id, client_id, file_path,
-                                    file_size, start_time);
-  store_->AddOrUpdateOfflinePage(
-      offline_page_item,
-      base::Bind(&OfflinePageModel::OnAddOfflinePageDone,
-                 weak_ptr_factory_.GetWeakPtr(), archiver, callback,
-                 offline_page_item));
-}
-
-void OfflinePageModel::OnAddOfflinePageDone(OfflinePageArchiver* archiver,
-                                            const SavePageCallback& callback,
-                                            const OfflinePageItem& offline_page,
-                                            bool success) {
-  SavePageResult result;
-  if (success) {
-    offline_pages_[offline_page.offline_id] = offline_page;
-    result = SavePageResult::SUCCESS;
-    UMA_HISTOGRAM_TIMES(
-        AddHistogramSuffix(
-            offline_page.client_id, "OfflinePages.SavePageTime").c_str(),
-        base::Time::Now() - offline_page.creation_time);
-    // 50 buckets capped between 1Kb and 10Mb.
-    UMA_HISTOGRAM_COUNTS_10000(AddHistogramSuffix(
-        offline_page.client_id, "OfflinePages.PageSize").c_str(),
-        offline_page.file_size / 1024);
-  } else {
-    result = SavePageResult::STORE_FAILURE;
-  }
-  InformSavePageDone(callback, result, offline_page.client_id,
-                     offline_page.offline_id);
-  DeletePendingArchiver(archiver);
-
-  FOR_EACH_OBSERVER(Observer, observers_, OfflinePageModelChanged(this));
-}
-
-void OfflinePageModel::OnMarkPageAccesseDone(
-    const OfflinePageItem& offline_page_item, bool success) {
-  // Update the item in the cache only upon success.
-  if (success)
-    offline_pages_[offline_page_item.offline_id] = offline_page_item;
-
-  // No need to fire OfflinePageModelChanged event since updating access info
-  // should not have any impact to the UI.
-}
-
-void OfflinePageModel::OnEnsureArchivesDirCreatedDone(
-    const base::TimeTicks& start_time) {
-  UMA_HISTOGRAM_TIMES("OfflinePages.Model.ArchiveDirCreationTime",
-                      base::TimeTicks::Now() - start_time);
-
-  store_->Load(base::Bind(&OfflinePageModel::OnLoadDone,
-                          weak_ptr_factory_.GetWeakPtr(), start_time));
-}
-
-void OfflinePageModel::OnLoadDone(
-    const base::TimeTicks& start_time,
-    OfflinePageMetadataStore::LoadStatus load_status,
-    const std::vector<OfflinePageItem>& offline_pages) {
-  DCHECK(!is_loaded_);
-  is_loaded_ = true;
-
-  // TODO(jianli): rebuild the store upon failure.
-
-  if (load_status == OfflinePageMetadataStore::LOAD_SUCCEEDED)
-    CacheLoadedData(offline_pages);
-
-  UMA_HISTOGRAM_TIMES("OfflinePages.Model.ConstructionToLoadedEventTime",
-                      base::TimeTicks::Now() - start_time);
-
-  // Create Storage Manager.
-  storage_manager_.reset(new OfflinePageStorageManager(
-      this, GetPolicyController(), archive_manager_.get()));
-
-  // Run all the delayed tasks.
-  for (const auto& delayed_task : delayed_tasks_)
-    delayed_task.Run();
-  delayed_tasks_.clear();
-
-  FOR_EACH_OBSERVER(Observer, observers_, OfflinePageModelLoaded(this));
-
-  CheckForExternalFileDeletion();
-}
-
-void OfflinePageModel::InformSavePageDone(const SavePageCallback& callback,
-                                          SavePageResult result,
-                                          const ClientId& client_id,
-                                          int64_t offline_id) {
-  UMA_HISTOGRAM_ENUMERATION(
-      AddHistogramSuffix(client_id, "OfflinePages.SavePageResult").c_str(),
-      static_cast<int>(result),
-      static_cast<int>(SavePageResult::RESULT_COUNT));
-  archive_manager_->GetStorageStats(
-      base::Bind(&ReportStorageHistogramsAfterSave));
-  callback.Run(result, offline_id);
-}
-
-void OfflinePageModel::DeletePendingArchiver(OfflinePageArchiver* archiver) {
-  pending_archivers_.erase(std::find(
-      pending_archivers_.begin(), pending_archivers_.end(), archiver));
-}
-
-void OfflinePageModel::OnDeleteArchiveFilesDone(
-    const std::vector<int64_t>& offline_ids,
-    const DeletePageCallback& callback,
-    bool success) {
-  if (!success) {
-    InformDeletePageDone(callback, DeletePageResult::DEVICE_FAILURE);
-    return;
-  }
-
-  store_->RemoveOfflinePages(
-      offline_ids,
-      base::Bind(&OfflinePageModel::OnRemoveOfflinePagesDone,
-                 weak_ptr_factory_.GetWeakPtr(), offline_ids, callback));
-}
-
-void OfflinePageModel::OnRemoveOfflinePagesDone(
-    const std::vector<int64_t>& offline_ids,
-    const DeletePageCallback& callback,
-    bool success) {
-  // Delete the offline page from the in memory cache regardless of success in
-  // store.
-  base::Time now = base::Time::Now();
-  int64_t total_size = 0;
-  for (int64_t offline_id : offline_ids) {
-    auto iter = offline_pages_.find(offline_id);
-    if (iter == offline_pages_.end())
-      continue;
-    total_size += iter->second.file_size;
-    ClientId client_id = iter->second.client_id;
-    UMA_HISTOGRAM_CUSTOM_COUNTS(
-        AddHistogramSuffix(client_id, "OfflinePages.PageLifetime").c_str(),
-        (now - iter->second.creation_time).InMinutes(),
-        1,
-        base::TimeDelta::FromDays(365).InMinutes(),
-        100);
-    UMA_HISTOGRAM_CUSTOM_COUNTS(
-        AddHistogramSuffix(
-            client_id, "OfflinePages.DeletePage.TimeSinceLastOpen").c_str(),
-        (now - iter->second.last_access_time).InMinutes(),
-        1,
-        base::TimeDelta::FromDays(365).InMinutes(),
-        100);
-    UMA_HISTOGRAM_CUSTOM_COUNTS(
-        AddHistogramSuffix(
-            client_id, "OfflinePages.DeletePage.LastOpenToCreated").c_str(),
-        (iter->second.last_access_time - iter->second.creation_time).
-            InMinutes(),
-        1,
-        base::TimeDelta::FromDays(365).InMinutes(),
-        100);
-    UMA_HISTOGRAM_MEMORY_KB(
-        AddHistogramSuffix(
-            client_id, "OfflinePages.DeletePage.PageSize").c_str(),
-        iter->second.file_size / 1024);
-    UMA_HISTOGRAM_COUNTS(
-        AddHistogramSuffix(
-            client_id, "OfflinePages.DeletePage.AccessCount").c_str(),
-        iter->second.access_count);
-    FOR_EACH_OBSERVER(
-        Observer, observers_,
-        OfflinePageDeleted(iter->second.offline_id, iter->second.client_id));
-    offline_pages_.erase(iter);
-  }
-  if (offline_ids.size() > 1) {
-    UMA_HISTOGRAM_COUNTS("OfflinePages.BatchDelete.Count",
-                         static_cast<int32_t>(offline_ids.size()));
-    UMA_HISTOGRAM_MEMORY_KB(
-        "OfflinePages.BatchDelete.TotalPageSize", total_size / 1024);
-  }
-  // Deleting multiple pages always succeeds when it gets to this point.
-  InformDeletePageDone(callback, (success || offline_ids.size() > 1)
-                                     ? DeletePageResult::SUCCESS
-                                     : DeletePageResult::STORE_FAILURE);
-}
-
-void OfflinePageModel::InformDeletePageDone(const DeletePageCallback& callback,
-                                            DeletePageResult result) {
-  UMA_HISTOGRAM_ENUMERATION(
-      "OfflinePages.DeletePageResult",
-      static_cast<int>(result),
-      static_cast<int>(DeletePageResult::RESULT_COUNT));
-  archive_manager_->GetStorageStats(
-      base::Bind(&ReportStorageHistogramsAfterDelete));
-  if (!callback.is_null())
-    callback.Run(result);
-}
-
-void OfflinePageModel::ScanForMissingArchiveFiles(
-    const std::set<base::FilePath>& archive_paths) {
-  std::vector<int64_t> ids_of_pages_missing_archive_file;
-  std::vector<std::pair<int64_t, ClientId>> offline_client_id_pairs;
-  for (const auto& id_page_pair : offline_pages_) {
-    if (archive_paths.count(id_page_pair.second.file_path) == 0UL) {
-      ids_of_pages_missing_archive_file.push_back(id_page_pair.first);
-      offline_client_id_pairs.push_back(
-          std::make_pair(id_page_pair.first, id_page_pair.second.client_id));
-    }
-  }
-
-  // No offline pages missing archive files, we can bail out.
-  if (ids_of_pages_missing_archive_file.empty())
-    return;
-
-  DeletePageCallback remove_pages_done_callback(
-      base::Bind(&OfflinePageModel::OnRemoveOfflinePagesMissingArchiveFileDone,
-                 weak_ptr_factory_.GetWeakPtr(), offline_client_id_pairs));
-
-  store_->RemoveOfflinePages(
-      ids_of_pages_missing_archive_file,
-      base::Bind(&OfflinePageModel::OnRemoveOfflinePagesDone,
-                 weak_ptr_factory_.GetWeakPtr(),
-                 ids_of_pages_missing_archive_file,
-                 remove_pages_done_callback));
-}
-
-void OfflinePageModel::OnRemoveOfflinePagesMissingArchiveFileDone(
-    const std::vector<std::pair<int64_t, ClientId>>& offline_client_id_pairs,
-    DeletePageResult /* result */) {
-  for (const auto& id_pair : offline_client_id_pairs) {
-    FOR_EACH_OBSERVER(Observer, observers_,
-                      OfflinePageDeleted(id_pair.first, id_pair.second));
-  }
-}
-
-void OfflinePageModel::OnRemoveAllFilesDoneForClearAll(
-    const base::Closure& callback,
-    DeletePageResult result) {
-  store_->Reset(base::Bind(&OfflinePageModel::OnResetStoreDoneForClearAll,
-                           weak_ptr_factory_.GetWeakPtr(),
-                           callback));
-}
-
-void OfflinePageModel::OnResetStoreDoneForClearAll(
-    const base::Closure& callback, bool success) {
-  DCHECK(success);
-  if (!success) {
-    UMA_HISTOGRAM_ENUMERATION("OfflinePages.ClearAllStatus2",
-                              STORE_RESET_FAILED,
-                              CLEAR_ALL_STATUS_COUNT);
-  }
-
-  offline_pages_.clear();
-  store_->Load(base::Bind(&OfflinePageModel::OnReloadStoreDoneForClearAll,
-                          weak_ptr_factory_.GetWeakPtr(),
-                          callback));
-}
-
-void OfflinePageModel::OnReloadStoreDoneForClearAll(
-    const base::Closure& callback,
-    OfflinePageMetadataStore::LoadStatus load_status,
-    const std::vector<OfflinePageItem>& offline_pages) {
-  DCHECK_EQ(OfflinePageMetadataStore::LOAD_SUCCEEDED, load_status);
-  UMA_HISTOGRAM_ENUMERATION(
-      "OfflinePages.ClearAllStatus2",
-      load_status == OfflinePageMetadataStore::LOAD_SUCCEEDED ?
-          CLEAR_ALL_SUCCEEDED : STORE_RELOAD_FAILED,
-      CLEAR_ALL_STATUS_COUNT);
-
-  CacheLoadedData(offline_pages);
-  callback.Run();
-}
-
-void OfflinePageModel::CacheLoadedData(
-    const std::vector<OfflinePageItem>& offline_pages) {
-  offline_pages_.clear();
-  for (const auto& offline_page : offline_pages)
-    offline_pages_[offline_page.offline_id] = offline_page;
-}
-
-int64_t OfflinePageModel::GenerateOfflineId() {
-  return base::RandGenerator(std::numeric_limits<int64_t>::max()) + 1;
-}
-
-void OfflinePageModel::RunWhenLoaded(const base::Closure& task) {
-  if (!is_loaded_) {
-    delayed_tasks_.push_back(task);
-    return;
-  }
-
-  base::ThreadTaskRunnerHandle::Get()->PostTask(FROM_HERE, task);
-}
+OfflinePageModel::~OfflinePageModel() {}
 
 }  // namespace offline_pages