Revert of Moves SQLitePersistentCookieStore to net/extras/sqlite.

content/browser/net/sqlite_persistent_cookie_store.cc

Index: content/browser/net/sqlite_persistent_cookie_store.cc
diff --git a/content/browser/net/sqlite_persistent_cookie_store.cc b/content/browser/net/sqlite_persistent_cookie_store.cc
new file mode 100644
index 0000000000000000000000000000000000000000..19731654fc8e41624676f62c824387ec82e2b453
--- /dev/null
+++ b/content/browser/net/sqlite_persistent_cookie_store.cc
@@ -0,0 +1,1465 @@
+// Copyright (c) 2012 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 "content/browser/net/sqlite_persistent_cookie_store.h"
+
+#include <list>
+#include <map>
+#include <set>
+#include <utility>
+
+#include "base/basictypes.h"
+#include "base/bind.h"
+#include "base/callback.h"
+#include "base/files/file_path.h"
+#include "base/files/file_util.h"
+#include "base/location.h"
+#include "base/logging.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/metrics/field_trial.h"
+#include "base/metrics/histogram.h"
+#include "base/profiler/scoped_tracker.h"
+#include "base/sequenced_task_runner.h"
+#include "base/strings/string_util.h"
+#include "base/strings/stringprintf.h"
+#include "base/synchronization/lock.h"
+#include "base/threading/sequenced_worker_pool.h"
+#include "base/time/time.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/cookie_store_factory.h"
+#include "net/base/registry_controlled_domains/registry_controlled_domain.h"
+#include "net/cookies/canonical_cookie.h"
+#include "net/cookies/cookie_constants.h"
+#include "net/cookies/cookie_util.h"
+#include "net/extras/sqlite/cookie_crypto_delegate.h"
+#include "sql/error_delegate_util.h"
+#include "sql/meta_table.h"
+#include "sql/statement.h"
+#include "sql/transaction.h"
+#include "storage/browser/quota/special_storage_policy.h"
+#include "third_party/sqlite/sqlite3.h"
+#include "url/gurl.h"
+
+using base::Time;
+
+namespace {
+
+// The persistent cookie store is loaded into memory on eTLD at a time. This
+// variable controls the delay between loading eTLDs, so as to not overload the
+// CPU or I/O with these low priority requests immediately after start up.
+const int kLoadDelayMilliseconds = 0;
+
+}  // namespace
+
+namespace content {
+
+// This class is designed to be shared between any client thread and the
+// background task runner. It batches operations and commits them on a timer.
+//
+// SQLitePersistentCookieStore::Load is called to load all cookies.  It
+// delegates to Backend::Load, which posts a Backend::LoadAndNotifyOnDBThread
+// task to the background runner.  This task calls Backend::ChainLoadCookies(),
+// which repeatedly posts itself to the BG runner to load each eTLD+1's cookies
+// in separate tasks.  When this is complete, Backend::CompleteLoadOnIOThread is
+// posted to the client runner, which notifies the caller of
+// SQLitePersistentCookieStore::Load that the load is complete.
+//
+// If a priority load request is invoked via SQLitePersistentCookieStore::
+// LoadCookiesForKey, it is delegated to Backend::LoadCookiesForKey, which posts
+// Backend::LoadKeyAndNotifyOnDBThread to the BG runner. That routine loads just
+// that single domain key (eTLD+1)'s cookies, and posts a Backend::
+// CompleteLoadForKeyOnIOThread to the client runner to notify the caller of
+// SQLitePersistentCookieStore::LoadCookiesForKey that that load is complete.
+//
+// Subsequent to loading, mutations may be queued by any thread using
+// AddCookie, UpdateCookieAccessTime, and DeleteCookie. These are flushed to
+// disk on the BG runner every 30 seconds, 512 operations, or call to Flush(),
+// whichever occurs first.
+class SQLitePersistentCookieStore::Backend
+    : public base::RefCountedThreadSafe<SQLitePersistentCookieStore::Backend> {
+ public:
+  Backend(
+      const base::FilePath& path,
+      const scoped_refptr<base::SequencedTaskRunner>& client_task_runner,
+      const scoped_refptr<base::SequencedTaskRunner>& background_task_runner,
+      bool restore_old_session_cookies,
+      storage::SpecialStoragePolicy* special_storage_policy,
+      net::CookieCryptoDelegate* crypto_delegate)
+      : path_(path),
+        num_pending_(0),
+        force_keep_session_state_(false),
+        initialized_(false),
+        corruption_detected_(false),
+        restore_old_session_cookies_(restore_old_session_cookies),
+        special_storage_policy_(special_storage_policy),
+        num_cookies_read_(0),
+        client_task_runner_(client_task_runner),
+        background_task_runner_(background_task_runner),
+        num_priority_waiting_(0),
+        total_priority_requests_(0),
+        crypto_(crypto_delegate) {}
+
+  // Creates or loads the SQLite database.
+  void Load(const LoadedCallback& loaded_callback);
+
+  // Loads cookies for the domain key (eTLD+1).
+  void LoadCookiesForKey(const std::string& domain,
+      const LoadedCallback& loaded_callback);
+
+  // Steps through all results of |smt|, makes a cookie from each, and adds the
+  // cookie to |cookies|. This method also updates |cookies_per_origin_| and
+  // |num_cookies_read_|.
+  void MakeCookiesFromSQLStatement(std::vector<net::CanonicalCookie*>* cookies,
+                                   sql::Statement* statement);
+
+  // Batch a cookie addition.
+  void AddCookie(const net::CanonicalCookie& cc);
+
+  // Batch a cookie access time update.
+  void UpdateCookieAccessTime(const net::CanonicalCookie& cc);
+
+  // Batch a cookie deletion.
+  void DeleteCookie(const net::CanonicalCookie& cc);
+
+  // Commit pending operations as soon as possible.
+  void Flush(const base::Closure& callback);
+
+  // Commit any pending operations and close the database.  This must be called
+  // before the object is destructed.
+  void Close();
+
+  void SetForceKeepSessionState();
+
+ private:
+  friend class base::RefCountedThreadSafe<SQLitePersistentCookieStore::Backend>;
+
+  // You should call Close() before destructing this object.
+  ~Backend() {
+    DCHECK(!db_.get()) << "Close should have already been called.";
+    DCHECK(num_pending_ == 0 && pending_.empty());
+
+    for (net::CanonicalCookie* cookie : cookies_) {
+      delete cookie;
+    }
+  }
+
+  // Database upgrade statements.
+  bool EnsureDatabaseVersion();
+
+  class PendingOperation {
+   public:
+    typedef enum {
+      COOKIE_ADD,
+      COOKIE_UPDATEACCESS,
+      COOKIE_DELETE,
+    } OperationType;
+
+    PendingOperation(OperationType op, const net::CanonicalCookie& cc)
+        : op_(op), cc_(cc) { }
+
+    OperationType op() const { return op_; }
+    const net::CanonicalCookie& cc() const { return cc_; }
+
+   private:
+    OperationType op_;
+    net::CanonicalCookie cc_;
+  };
+
+ private:
+  // Creates or loads the SQLite database on background runner.
+  void LoadAndNotifyInBackground(const LoadedCallback& loaded_callback,
+                                 const base::Time& posted_at);
+
+  // Loads cookies for the domain key (eTLD+1) on background runner.
+  void LoadKeyAndNotifyInBackground(const std::string& domains,
+                                    const LoadedCallback& loaded_callback,
+                                    const base::Time& posted_at);
+
+  // Notifies the CookieMonster when loading completes for a specific domain key
+  // or for all domain keys. Triggers the callback and passes it all cookies
+  // that have been loaded from DB since last IO notification.
+  void Notify(const LoadedCallback& loaded_callback, bool load_success);
+
+  // Sends notification when the entire store is loaded, and reports metrics
+  // for the total time to load and aggregated results from any priority loads
+  // that occurred.
+  void CompleteLoadInForeground(const LoadedCallback& loaded_callback,
+                                bool load_success);
+
+  // Sends notification when a single priority load completes. Updates priority
+  // load metric data. The data is sent only after the final load completes.
+  void CompleteLoadForKeyInForeground(const LoadedCallback& loaded_callback,
+                                      bool load_success,
+                                      const base::Time& requested_at);
+
+  // Sends all metrics, including posting a ReportMetricsInBackground task.
+  // Called after all priority and regular loading is complete.
+  void ReportMetrics();
+
+  // Sends background-runner owned metrics (i.e., the combined duration of all
+  // BG-runner tasks).
+  void ReportMetricsInBackground();
+
+  // Initialize the data base.
+  bool InitializeDatabase();
+
+  // Loads cookies for the next domain key from the DB, then either reschedules
+  // itself or schedules the provided callback to run on the client runner (if
+  // all domains are loaded).
+  void ChainLoadCookies(const LoadedCallback& loaded_callback);
+
+  // Load all cookies for a set of domains/hosts
+  bool LoadCookiesForDomains(const std::set<std::string>& key);
+
+  // Batch a cookie operation (add or delete)
+  void BatchOperation(PendingOperation::OperationType op,
+                      const net::CanonicalCookie& cc);
+  // Commit our pending operations to the database.
+  void Commit();
+  // Close() executed on the background runner.
+  void InternalBackgroundClose();
+
+  void DeleteSessionCookiesOnStartup();
+
+  void DeleteSessionCookiesOnShutdown();
+
+  void DatabaseErrorCallback(int error, sql::Statement* stmt);
+  void KillDatabase();
+
+  void PostBackgroundTask(const tracked_objects::Location& origin,
+                          const base::Closure& task);
+  void PostClientTask(const tracked_objects::Location& origin,
+                      const base::Closure& task);
+
+  // Shared code between the different load strategies to be used after all
+  // cookies have been loaded.
+  void FinishedLoadingCookies(const LoadedCallback& loaded_callback,
+                              bool success);
+
+  base::FilePath path_;
+  scoped_ptr<sql::Connection> db_;
+  sql::MetaTable meta_table_;
+
+  typedef std::list<PendingOperation*> PendingOperationsList;
+  PendingOperationsList pending_;
+  PendingOperationsList::size_type num_pending_;
+  // True if the persistent store should skip delete on exit rules.
+  bool force_keep_session_state_;
+  // Guard |cookies_|, |pending_|, |num_pending_|, |force_keep_session_state_|
+  base::Lock lock_;
+
+  // Temporary buffer for cookies loaded from DB. Accumulates cookies to reduce
+  // the number of messages sent to the client runner. Sent back in response to
+  // individual load requests for domain keys or when all loading completes.
+  // Ownership of the cookies in this vector is transferred to the client in
+  // response to individual load requests or when all loading completes.
+  std::vector<net::CanonicalCookie*> cookies_;
+
+  // Map of domain keys(eTLD+1) to domains/hosts that are to be loaded from DB.
+  std::map<std::string, std::set<std::string> > keys_to_load_;
+
+  // Map of (domain keys(eTLD+1), is secure cookie) to number of cookies in the
+  // database.
+  typedef std::pair<std::string, bool> CookieOrigin;
+  typedef std::map<CookieOrigin, int> CookiesPerOriginMap;
+  CookiesPerOriginMap cookies_per_origin_;
+
+  // Indicates if DB has been initialized.
+  bool initialized_;
+
+  // Indicates if the kill-database callback has been scheduled.
+  bool corruption_detected_;
+
+  // If false, we should filter out session cookies when reading the DB.
+  bool restore_old_session_cookies_;
+
+  // Policy defining what data is deleted on shutdown.
+  scoped_refptr<storage::SpecialStoragePolicy> special_storage_policy_;
+
+  // The cumulative time spent loading the cookies on the background runner.
+  // Incremented and reported from the background runner.
+  base::TimeDelta cookie_load_duration_;
+
+  // The total number of cookies read. Incremented and reported on the
+  // background runner.
+  int num_cookies_read_;
+
+  scoped_refptr<base::SequencedTaskRunner> client_task_runner_;
+  scoped_refptr<base::SequencedTaskRunner> background_task_runner_;
+
+  // Guards the following metrics-related properties (only accessed when
+  // starting/completing priority loads or completing the total load).
+  base::Lock metrics_lock_;
+  int num_priority_waiting_;
+  // The total number of priority requests.
+  int total_priority_requests_;
+  // The time when |num_priority_waiting_| incremented to 1.
+  base::Time current_priority_wait_start_;
+  // The cumulative duration of time when |num_priority_waiting_| was greater
+  // than 1.
+  base::TimeDelta priority_wait_duration_;
+  // Class with functions that do cryptographic operations (for protecting
+  // cookies stored persistently).
+  //
+  // Not owned.
+  net::CookieCryptoDelegate* crypto_;
+
+  DISALLOW_COPY_AND_ASSIGN(Backend);
+};
+
+namespace {
+
+// Version number of the database.
+//
+// Version 9 adds a partial index to track non-persistent cookies.
+// Non-persistent cookies sometimes need to be deleted on startup. There are
+// frequently few or no non-persistent cookies, so the partial index allows the
+// deletion to be sped up or skipped, without having to page in the DB.
+//
+// Version 8 adds "first-party only" cookies.
+//
+// Version 7 adds encrypted values.  Old values will continue to be used but
+// all new values written will be encrypted on selected operating systems.  New
+// records read by old clients will simply get an empty cookie value while old
+// records read by new clients will continue to operate with the unencrypted
+// version.  New and old clients alike will always write/update records with
+// what they support.
+//
+// Version 6 adds cookie priorities. This allows developers to influence the
+// order in which cookies are evicted in order to meet domain cookie limits.
+//
+// Version 5 adds the columns has_expires and is_persistent, so that the
+// database can store session cookies as well as persistent cookies. Databases
+// of version 5 are incompatible with older versions of code. If a database of
+// version 5 is read by older code, session cookies will be treated as normal
+// cookies. Currently, these fields are written, but not read anymore.
+//
+// In version 4, we migrated the time epoch.  If you open the DB with an older
+// version on Mac or Linux, the times will look wonky, but the file will likely
+// be usable. On Windows version 3 and 4 are the same.
+//
+// Version 3 updated the database to include the last access time, so we can
+// expire them in decreasing order of use when we've reached the maximum
+// number of cookies.
+const int kCurrentVersionNumber = 9;
+const int kCompatibleVersionNumber = 5;
+
+// Possible values for the 'priority' column.
+enum DBCookiePriority {
+  kCookiePriorityLow = 0,
+  kCookiePriorityMedium = 1,
+  kCookiePriorityHigh = 2,
+};
+
+DBCookiePriority CookiePriorityToDBCookiePriority(net::CookiePriority value) {
+  switch (value) {
+    case net::COOKIE_PRIORITY_LOW:
+      return kCookiePriorityLow;
+    case net::COOKIE_PRIORITY_MEDIUM:
+      return kCookiePriorityMedium;
+    case net::COOKIE_PRIORITY_HIGH:
+      return kCookiePriorityHigh;
+  }
+
+  NOTREACHED();
+  return kCookiePriorityMedium;
+}
+
+net::CookiePriority DBCookiePriorityToCookiePriority(DBCookiePriority value) {
+  switch (value) {
+    case kCookiePriorityLow:
+      return net::COOKIE_PRIORITY_LOW;
+    case kCookiePriorityMedium:
+      return net::COOKIE_PRIORITY_MEDIUM;
+    case kCookiePriorityHigh:
+      return net::COOKIE_PRIORITY_HIGH;
+  }
+
+  NOTREACHED();
+  return net::COOKIE_PRIORITY_DEFAULT;
+}
+
+// Increments a specified TimeDelta by the duration between this object's
+// constructor and destructor. Not thread safe. Multiple instances may be
+// created with the same delta instance as long as their lifetimes are nested.
+// The shortest lived instances have no impact.
+class IncrementTimeDelta {
+ public:
+  explicit IncrementTimeDelta(base::TimeDelta* delta) :
+      delta_(delta),
+      original_value_(*delta),
+      start_(base::Time::Now()) {}
+
+  ~IncrementTimeDelta() {
+    *delta_ = original_value_ + base::Time::Now() - start_;
+  }
+
+ private:
+  base::TimeDelta* delta_;
+  base::TimeDelta original_value_;
+  base::Time start_;
+
+  DISALLOW_COPY_AND_ASSIGN(IncrementTimeDelta);
+};
+
+// Initializes the cookies table, returning true on success.
+bool InitTable(sql::Connection* db) {
+  if (db->DoesTableExist("cookies"))
+    return true;
+
+  std::string stmt(base::StringPrintf(
+      "CREATE TABLE cookies ("
+      "creation_utc INTEGER NOT NULL UNIQUE PRIMARY KEY,"
+      "host_key TEXT NOT NULL,"
+      "name TEXT NOT NULL,"
+      "value TEXT NOT NULL,"
+      "path TEXT NOT NULL,"
+      "expires_utc INTEGER NOT NULL,"
+      "secure INTEGER NOT NULL,"
+      "httponly INTEGER NOT NULL,"
+      "last_access_utc INTEGER NOT NULL, "
+      "has_expires INTEGER NOT NULL DEFAULT 1, "
+      "persistent INTEGER NOT NULL DEFAULT 1,"
+      "priority INTEGER NOT NULL DEFAULT %d,"
+      "encrypted_value BLOB DEFAULT '',"
+      "firstpartyonly INTEGER NOT NULL DEFAULT 0)",
+      CookiePriorityToDBCookiePriority(net::COOKIE_PRIORITY_DEFAULT)));
+  if (!db->Execute(stmt.c_str()))
+    return false;
+
+  if (!db->Execute("CREATE INDEX domain ON cookies(host_key)"))
+    return false;
+
+#if defined(OS_IOS)
+  // iOS 8.1 and older doesn't support partial indices. iOS 8.2 supports
+  // partial indices.
+  if (!db->Execute("CREATE INDEX is_transient ON cookies(persistent)")) {
+#else
+  if (!db->Execute(
+          "CREATE INDEX is_transient ON cookies(persistent) "
+          "where persistent != 1")) {
+#endif
+    return false;
+  }
+
+  return true;
+}
+
+}  // namespace
+
+void SQLitePersistentCookieStore::Backend::Load(
+    const LoadedCallback& loaded_callback) {
+  PostBackgroundTask(FROM_HERE, base::Bind(
+      &Backend::LoadAndNotifyInBackground, this,
+      loaded_callback, base::Time::Now()));
+}
+
+void SQLitePersistentCookieStore::Backend::LoadCookiesForKey(
+    const std::string& key,
+    const LoadedCallback& loaded_callback) {
+  {
+    base::AutoLock locked(metrics_lock_);
+    if (num_priority_waiting_ == 0)
+      current_priority_wait_start_ = base::Time::Now();
+    num_priority_waiting_++;
+    total_priority_requests_++;
+  }
+
+  PostBackgroundTask(FROM_HERE, base::Bind(
+      &Backend::LoadKeyAndNotifyInBackground,
+      this, key, loaded_callback, base::Time::Now()));
+}
+
+void SQLitePersistentCookieStore::Backend::LoadAndNotifyInBackground(
+    const LoadedCallback& loaded_callback, const base::Time& posted_at) {
+  DCHECK(background_task_runner_->RunsTasksOnCurrentThread());
+  IncrementTimeDelta increment(&cookie_load_duration_);
+
+  UMA_HISTOGRAM_CUSTOM_TIMES(
+      "Cookie.TimeLoadDBQueueWait",
+      base::Time::Now() - posted_at,
+      base::TimeDelta::FromMilliseconds(1), base::TimeDelta::FromMinutes(1),
+      50);
+
+  if (!InitializeDatabase()) {
+    PostClientTask(FROM_HERE, base::Bind(
+        &Backend::CompleteLoadInForeground, this, loaded_callback, false));
+  } else {
+    ChainLoadCookies(loaded_callback);
+  }
+}
+
+void SQLitePersistentCookieStore::Backend::LoadKeyAndNotifyInBackground(
+    const std::string& key,
+    const LoadedCallback& loaded_callback,
+    const base::Time& posted_at) {
+  DCHECK(background_task_runner_->RunsTasksOnCurrentThread());
+  IncrementTimeDelta increment(&cookie_load_duration_);
+
+  UMA_HISTOGRAM_CUSTOM_TIMES(
+      "Cookie.TimeKeyLoadDBQueueWait",
+      base::Time::Now() - posted_at,
+      base::TimeDelta::FromMilliseconds(1), base::TimeDelta::FromMinutes(1),
+      50);
+
+  bool success = false;
+  if (InitializeDatabase()) {
+    std::map<std::string, std::set<std::string> >::iterator
+      it = keys_to_load_.find(key);
+    if (it != keys_to_load_.end()) {
+      success = LoadCookiesForDomains(it->second);
+      keys_to_load_.erase(it);
+    } else {
+      success = true;
+    }
+  }
+
+  PostClientTask(FROM_HERE, base::Bind(
+      &SQLitePersistentCookieStore::Backend::CompleteLoadForKeyInForeground,
+      this, loaded_callback, success, posted_at));
+}
+
+void SQLitePersistentCookieStore::Backend::CompleteLoadForKeyInForeground(
+    const LoadedCallback& loaded_callback,
+    bool load_success,
+    const::Time& requested_at) {
+  DCHECK(client_task_runner_->RunsTasksOnCurrentThread());
+
+  UMA_HISTOGRAM_CUSTOM_TIMES(
+      "Cookie.TimeKeyLoadTotalWait",
+      base::Time::Now() - requested_at,
+      base::TimeDelta::FromMilliseconds(1), base::TimeDelta::FromMinutes(1),
+      50);
+
+  Notify(loaded_callback, load_success);
+
+  {
+    base::AutoLock locked(metrics_lock_);
+    num_priority_waiting_--;
+    if (num_priority_waiting_ == 0) {
+      priority_wait_duration_ +=
+          base::Time::Now() - current_priority_wait_start_;
+    }
+  }
+
+}
+
+void SQLitePersistentCookieStore::Backend::ReportMetricsInBackground() {
+  UMA_HISTOGRAM_CUSTOM_TIMES(
+      "Cookie.TimeLoad",
+      cookie_load_duration_,
+      base::TimeDelta::FromMilliseconds(1), base::TimeDelta::FromMinutes(1),
+      50);
+}
+
+void SQLitePersistentCookieStore::Backend::ReportMetrics() {
+  PostBackgroundTask(FROM_HERE, base::Bind(
+      &SQLitePersistentCookieStore::Backend::ReportMetricsInBackground, this));
+
+  {
+    base::AutoLock locked(metrics_lock_);
+    UMA_HISTOGRAM_CUSTOM_TIMES(
+        "Cookie.PriorityBlockingTime",
+        priority_wait_duration_,
+        base::TimeDelta::FromMilliseconds(1), base::TimeDelta::FromMinutes(1),
+        50);
+
+    UMA_HISTOGRAM_COUNTS_100(
+        "Cookie.PriorityLoadCount",
+        total_priority_requests_);
+
+    UMA_HISTOGRAM_COUNTS_10000(
+        "Cookie.NumberOfLoadedCookies",
+        num_cookies_read_);
+  }
+}
+
+void SQLitePersistentCookieStore::Backend::CompleteLoadInForeground(
+    const LoadedCallback& loaded_callback, bool load_success) {
+  Notify(loaded_callback, load_success);
+
+  if (load_success)
+    ReportMetrics();
+}
+
+void SQLitePersistentCookieStore::Backend::Notify(
+    const LoadedCallback& loaded_callback,
+    bool load_success) {
+  DCHECK(client_task_runner_->RunsTasksOnCurrentThread());
+
+  std::vector<net::CanonicalCookie*> cookies;
+  {
+    base::AutoLock locked(lock_);
+    cookies.swap(cookies_);
+  }
+
+  loaded_callback.Run(cookies);
+}
+
+bool SQLitePersistentCookieStore::Backend::InitializeDatabase() {
+  DCHECK(background_task_runner_->RunsTasksOnCurrentThread());
+
+  if (initialized_ || corruption_detected_) {
+    // Return false if we were previously initialized but the DB has since been
+    // closed, or if corruption caused a database reset during initialization.
+    return db_ != NULL;
+  }
+
+  base::Time start = base::Time::Now();
+
+  const base::FilePath dir = path_.DirName();
+  if (!base::PathExists(dir) && !base::CreateDirectory(dir)) {
+    return false;
+  }
+
+  int64 db_size = 0;
+  if (base::GetFileSize(path_, &db_size))
+    UMA_HISTOGRAM_COUNTS("Cookie.DBSizeInKB", db_size / 1024 );
+
+  db_.reset(new sql::Connection);
+  db_->set_histogram_tag("Cookie");
+
+  // Unretained to avoid a ref loop with |db_|.
+  db_->set_error_callback(
+      base::Bind(&SQLitePersistentCookieStore::Backend::DatabaseErrorCallback,
+                 base::Unretained(this)));
+
+  if (!db_->Open(path_)) {
+    NOTREACHED() << "Unable to open cookie DB.";
+    if (corruption_detected_)
+      db_->Raze();
+    meta_table_.Reset();
+    db_.reset();
+    return false;
+  }
+
+  if (!EnsureDatabaseVersion() || !InitTable(db_.get())) {
+    NOTREACHED() << "Unable to open cookie DB.";
+    if (corruption_detected_)
+      db_->Raze();
+    meta_table_.Reset();
+    db_.reset();
+    return false;
+  }
+
+  UMA_HISTOGRAM_CUSTOM_TIMES(
+      "Cookie.TimeInitializeDB",
+      base::Time::Now() - start,
+      base::TimeDelta::FromMilliseconds(1), base::TimeDelta::FromMinutes(1),
+      50);
+
+  start = base::Time::Now();
+
+  // Retrieve all the domains
+  sql::Statement smt(db_->GetUniqueStatement(
+    "SELECT DISTINCT host_key FROM cookies"));
+
+  if (!smt.is_valid()) {
+    if (corruption_detected_)
+      db_->Raze();
+    meta_table_.Reset();
+    db_.reset();
+    return false;
+  }
+
+  std::vector<std::string> host_keys;
+  while (smt.Step())
+    host_keys.push_back(smt.ColumnString(0));
+
+  UMA_HISTOGRAM_CUSTOM_TIMES(
+      "Cookie.TimeLoadDomains",
+      base::Time::Now() - start,
+      base::TimeDelta::FromMilliseconds(1), base::TimeDelta::FromMinutes(1),
+      50);
+
+  base::Time start_parse = base::Time::Now();
+
+  // Build a map of domain keys (always eTLD+1) to domains.
+  for (size_t idx = 0; idx < host_keys.size(); ++idx) {
+    const std::string& domain = host_keys[idx];
+    std::string key =
+        net::registry_controlled_domains::GetDomainAndRegistry(
+            domain,
+            net::registry_controlled_domains::INCLUDE_PRIVATE_REGISTRIES);
+
+    keys_to_load_[key].insert(domain);
+  }
+
+  UMA_HISTOGRAM_CUSTOM_TIMES(
+      "Cookie.TimeParseDomains",
+      base::Time::Now() - start_parse,
+      base::TimeDelta::FromMilliseconds(1), base::TimeDelta::FromMinutes(1),
+      50);
+
+  UMA_HISTOGRAM_CUSTOM_TIMES(
+      "Cookie.TimeInitializeDomainMap",
+      base::Time::Now() - start,
+      base::TimeDelta::FromMilliseconds(1), base::TimeDelta::FromMinutes(1),
+      50);
+
+  initialized_ = true;
+
+  if (!restore_old_session_cookies_)
+    DeleteSessionCookiesOnStartup();
+  return true;
+}
+
+void SQLitePersistentCookieStore::Backend::ChainLoadCookies(
+    const LoadedCallback& loaded_callback) {
+  DCHECK(background_task_runner_->RunsTasksOnCurrentThread());
+  IncrementTimeDelta increment(&cookie_load_duration_);
+
+  bool load_success = true;
+
+  if (!db_) {
+    // Close() has been called on this store.
+    load_success = false;
+  } else if (keys_to_load_.size() > 0) {
+    // Load cookies for the first domain key.
+    std::map<std::string, std::set<std::string> >::iterator
+      it = keys_to_load_.begin();
+    load_success = LoadCookiesForDomains(it->second);
+    keys_to_load_.erase(it);
+  }
+
+  // If load is successful and there are more domain keys to be loaded,
+  // then post a background task to continue chain-load;
+  // Otherwise notify on client runner.
+  if (load_success && keys_to_load_.size() > 0) {
+    bool success = background_task_runner_->PostDelayedTask(
+        FROM_HERE,
+        base::Bind(&Backend::ChainLoadCookies, this, loaded_callback),
+        base::TimeDelta::FromMilliseconds(kLoadDelayMilliseconds));
+    if (!success) {
+      LOG(WARNING) << "Failed to post task from " << FROM_HERE.ToString()
+                   << " to background_task_runner_.";
+    }
+  } else {
+    FinishedLoadingCookies(loaded_callback, load_success);
+  }
+}
+
+bool SQLitePersistentCookieStore::Backend::LoadCookiesForDomains(
+  const std::set<std::string>& domains) {
+  DCHECK(background_task_runner_->RunsTasksOnCurrentThread());
+
+  sql::Statement smt;
+  if (restore_old_session_cookies_) {
+    smt.Assign(db_->GetCachedStatement(
+        SQL_FROM_HERE,
+        "SELECT creation_utc, host_key, name, value, encrypted_value, path, "
+        "expires_utc, secure, httponly, firstpartyonly, last_access_utc, "
+        "has_expires, persistent, priority FROM cookies WHERE host_key = ?"));
+  } else {
+    smt.Assign(db_->GetCachedStatement(
+        SQL_FROM_HERE,
+        "SELECT creation_utc, host_key, name, value, encrypted_value, path, "
+        "expires_utc, secure, httponly, firstpartyonly, last_access_utc, "
+        "has_expires, persistent, priority FROM cookies WHERE host_key = ? "
+        "AND persistent = 1"));
+  }
+  if (!smt.is_valid()) {
+    smt.Clear();  // Disconnect smt_ref from db_.
+    meta_table_.Reset();
+    db_.reset();
+    return false;
+  }
+
+  std::vector<net::CanonicalCookie*> cookies;
+  std::set<std::string>::const_iterator it = domains.begin();
+  for (; it != domains.end(); ++it) {
+    smt.BindString(0, *it);
+    MakeCookiesFromSQLStatement(&cookies, &smt);
+    smt.Reset(true);
+  }
+  {
+    base::AutoLock locked(lock_);
+    cookies_.insert(cookies_.end(), cookies.begin(), cookies.end());
+  }
+  return true;
+}
+
+void SQLitePersistentCookieStore::Backend::MakeCookiesFromSQLStatement(
+    std::vector<net::CanonicalCookie*>* cookies,
+    sql::Statement* statement) {
+  sql::Statement& smt = *statement;
+  while (smt.Step()) {
+    std::string value;
+    std::string encrypted_value = smt.ColumnString(4);
+    if (!encrypted_value.empty() && crypto_) {
+      crypto_->DecryptString(encrypted_value, &value);
+    } else {
+      DCHECK(encrypted_value.empty());
+      value = smt.ColumnString(3);
+    }
+    scoped_ptr<net::CanonicalCookie> cc(new net::CanonicalCookie(
+        // The "source" URL is not used with persisted cookies.
+        GURL(),                                        // Source
+        smt.ColumnString(2),                           // name
+        value,                                         // value
+        smt.ColumnString(1),                           // domain
+        smt.ColumnString(5),                           // path
+        Time::FromInternalValue(smt.ColumnInt64(0)),   // creation_utc
+        Time::FromInternalValue(smt.ColumnInt64(6)),   // expires_utc
+        Time::FromInternalValue(smt.ColumnInt64(10)),  // last_access_utc
+        smt.ColumnInt(7) != 0,                         // secure
+        smt.ColumnInt(8) != 0,                         // httponly
+        smt.ColumnInt(9) != 0,                         // firstpartyonly
+        DBCookiePriorityToCookiePriority(
+            static_cast<DBCookiePriority>(smt.ColumnInt(13)))));  // priority
+    DLOG_IF(WARNING, cc->CreationDate() > Time::Now())
+        << L"CreationDate too recent";
+    cookies_per_origin_[CookieOrigin(cc->Domain(), cc->IsSecure())]++;
+    cookies->push_back(cc.release());
+    ++num_cookies_read_;
+  }
+}
+
+bool SQLitePersistentCookieStore::Backend::EnsureDatabaseVersion() {
+  // Version check.
+  if (!meta_table_.Init(
+      db_.get(), kCurrentVersionNumber, kCompatibleVersionNumber)) {
+    return false;
+  }
+
+  if (meta_table_.GetCompatibleVersionNumber() > kCurrentVersionNumber) {
+    LOG(WARNING) << "Cookie database is too new.";
+    return false;
+  }
+
+  int cur_version = meta_table_.GetVersionNumber();
+  if (cur_version == 2) {
+    sql::Transaction transaction(db_.get());
+    if (!transaction.Begin())
+      return false;
+    if (!db_->Execute("ALTER TABLE cookies ADD COLUMN last_access_utc "
+                     "INTEGER DEFAULT 0") ||
+        !db_->Execute("UPDATE cookies SET last_access_utc = creation_utc")) {
+      LOG(WARNING) << "Unable to update cookie database to version 3.";
+      return false;
+    }
+    ++cur_version;
+    meta_table_.SetVersionNumber(cur_version);
+    meta_table_.SetCompatibleVersionNumber(
+        std::min(cur_version, kCompatibleVersionNumber));
+    transaction.Commit();
+  }
+
+  if (cur_version == 3) {
+    // The time epoch changed for Mac & Linux in this version to match Windows.
+    // This patch came after the main epoch change happened, so some
+    // developers have "good" times for cookies added by the more recent
+    // versions. So we have to be careful to only update times that are under
+    // the old system (which will appear to be from before 1970 in the new
+    // system). The magic number used below is 1970 in our time units.
+    sql::Transaction transaction(db_.get());
+    transaction.Begin();
+#if !defined(OS_WIN)
+    ignore_result(db_->Execute(
+        "UPDATE cookies "
+        "SET creation_utc = creation_utc + 11644473600000000 "
+        "WHERE rowid IN "
+        "(SELECT rowid FROM cookies WHERE "
+          "creation_utc > 0 AND creation_utc < 11644473600000000)"));
+    ignore_result(db_->Execute(
+        "UPDATE cookies "
+        "SET expires_utc = expires_utc + 11644473600000000 "
+        "WHERE rowid IN "
+        "(SELECT rowid FROM cookies WHERE "
+          "expires_utc > 0 AND expires_utc < 11644473600000000)"));
+    ignore_result(db_->Execute(
+        "UPDATE cookies "
+        "SET last_access_utc = last_access_utc + 11644473600000000 "
+        "WHERE rowid IN "
+        "(SELECT rowid FROM cookies WHERE "
+          "last_access_utc > 0 AND last_access_utc < 11644473600000000)"));
+#endif
+    ++cur_version;
+    meta_table_.SetVersionNumber(cur_version);
+    transaction.Commit();
+  }
+
+  if (cur_version == 4) {
+    const base::TimeTicks start_time = base::TimeTicks::Now();
+    sql::Transaction transaction(db_.get());
+    if (!transaction.Begin())
+      return false;
+    if (!db_->Execute("ALTER TABLE cookies "
+                      "ADD COLUMN has_expires INTEGER DEFAULT 1") ||
+        !db_->Execute("ALTER TABLE cookies "
+                      "ADD COLUMN persistent INTEGER DEFAULT 1")) {
+      LOG(WARNING) << "Unable to update cookie database to version 5.";
+      return false;
+    }
+    ++cur_version;
+    meta_table_.SetVersionNumber(cur_version);
+    meta_table_.SetCompatibleVersionNumber(
+        std::min(cur_version, kCompatibleVersionNumber));
+    transaction.Commit();
+    UMA_HISTOGRAM_TIMES("Cookie.TimeDatabaseMigrationToV5",
+                        base::TimeTicks::Now() - start_time);
+  }
+
+  if (cur_version == 5) {
+    const base::TimeTicks start_time = base::TimeTicks::Now();
+    sql::Transaction transaction(db_.get());
+    if (!transaction.Begin())
+      return false;
+    // Alter the table to add the priority column with a default value.
+    std::string stmt(base::StringPrintf(
+        "ALTER TABLE cookies ADD COLUMN priority INTEGER DEFAULT %d",
+        CookiePriorityToDBCookiePriority(net::COOKIE_PRIORITY_DEFAULT)));
+    if (!db_->Execute(stmt.c_str())) {
+      LOG(WARNING) << "Unable to update cookie database to version 6.";
+      return false;
+    }
+    ++cur_version;
+    meta_table_.SetVersionNumber(cur_version);
+    meta_table_.SetCompatibleVersionNumber(
+        std::min(cur_version, kCompatibleVersionNumber));
+    transaction.Commit();
+    UMA_HISTOGRAM_TIMES("Cookie.TimeDatabaseMigrationToV6",
+                        base::TimeTicks::Now() - start_time);
+  }
+
+  if (cur_version == 6) {
+    const base::TimeTicks start_time = base::TimeTicks::Now();
+    sql::Transaction transaction(db_.get());
+    if (!transaction.Begin())
+      return false;
+    // Alter the table to add empty "encrypted value" column.
+    if (!db_->Execute("ALTER TABLE cookies "
+                      "ADD COLUMN encrypted_value BLOB DEFAULT ''")) {
+      LOG(WARNING) << "Unable to update cookie database to version 7.";
+      return false;
+    }
+    ++cur_version;
+    meta_table_.SetVersionNumber(cur_version);
+    meta_table_.SetCompatibleVersionNumber(
+        std::min(cur_version, kCompatibleVersionNumber));
+    transaction.Commit();
+    UMA_HISTOGRAM_TIMES("Cookie.TimeDatabaseMigrationToV7",
+                        base::TimeTicks::Now() - start_time);
+  }
+
+  if (cur_version == 7) {
+    const base::TimeTicks start_time = base::TimeTicks::Now();
+    sql::Transaction transaction(db_.get());
+    if (!transaction.Begin())
+      return false;
+    // Alter the table to add a 'firstpartyonly' column.
+    if (!db_->Execute(
+            "ALTER TABLE cookies "
+            "ADD COLUMN firstpartyonly INTEGER DEFAULT 0")) {
+      LOG(WARNING) << "Unable to update cookie database to version 8.";
+      return false;
+    }
+    ++cur_version;
+    meta_table_.SetVersionNumber(cur_version);
+    meta_table_.SetCompatibleVersionNumber(
+        std::min(cur_version, kCompatibleVersionNumber));
+    transaction.Commit();
+    UMA_HISTOGRAM_TIMES("Cookie.TimeDatabaseMigrationToV8",
+                        base::TimeTicks::Now() - start_time);
+  }
+
+  if (cur_version == 8) {
+    const base::TimeTicks start_time = base::TimeTicks::Now();
+    sql::Transaction transaction(db_.get());
+    if (!transaction.Begin())
+      return false;
+
+    if (!db_->Execute("DROP INDEX IF EXISTS cookie_times")) {
+      LOG(WARNING)
+          << "Unable to drop table cookie_times in update to version 9.";
+      return false;
+    }
+
+    if (!db_->Execute(
+        "CREATE INDEX IF NOT EXISTS domain ON cookies(host_key)")) {
+      LOG(WARNING) << "Unable to create index domain in update to version 9.";
+      return false;
+    }
+
+#if defined(OS_IOS)
+    // iOS 8.1 and older doesn't support partial indices. iOS 8.2 supports
+    // partial indices.
+    if (!db_->Execute(
+        "CREATE INDEX IF NOT EXISTS is_transient ON cookies(persistent)")) {
+#else
+    if (!db_->Execute(
+        "CREATE INDEX IF NOT EXISTS is_transient ON cookies(persistent) "
+        "where persistent != 1")) {
+#endif
+      LOG(WARNING)
+          << "Unable to create index is_transient in update to version 9.";
+      return false;
+    }
+    ++cur_version;
+    meta_table_.SetVersionNumber(cur_version);
+    meta_table_.SetCompatibleVersionNumber(
+        std::min(cur_version, kCompatibleVersionNumber));
+    transaction.Commit();
+    UMA_HISTOGRAM_TIMES("Cookie.TimeDatabaseMigrationToV9",
+                        base::TimeTicks::Now() - start_time);
+  }
+
+  // Put future migration cases here.
+
+  if (cur_version < kCurrentVersionNumber) {
+    UMA_HISTOGRAM_COUNTS_100("Cookie.CorruptMetaTable", 1);
+
+    meta_table_.Reset();
+    db_.reset(new sql::Connection);
+    if (!sql::Connection::Delete(path_) ||
+        !db_->Open(path_) ||
+        !meta_table_.Init(
+            db_.get(), kCurrentVersionNumber, kCompatibleVersionNumber)) {
+      UMA_HISTOGRAM_COUNTS_100("Cookie.CorruptMetaTableRecoveryFailed", 1);
+      NOTREACHED() << "Unable to reset the cookie DB.";
+      meta_table_.Reset();
+      db_.reset();
+      return false;
+    }
+  }
+
+  return true;
+}
+
+void SQLitePersistentCookieStore::Backend::AddCookie(
+    const net::CanonicalCookie& cc) {
+  BatchOperation(PendingOperation::COOKIE_ADD, cc);
+}
+
+void SQLitePersistentCookieStore::Backend::UpdateCookieAccessTime(
+    const net::CanonicalCookie& cc) {
+  BatchOperation(PendingOperation::COOKIE_UPDATEACCESS, cc);
+}
+
+void SQLitePersistentCookieStore::Backend::DeleteCookie(
+    const net::CanonicalCookie& cc) {
+  BatchOperation(PendingOperation::COOKIE_DELETE, cc);
+}
+
+void SQLitePersistentCookieStore::Backend::BatchOperation(
+    PendingOperation::OperationType op,
+    const net::CanonicalCookie& cc) {
+  // Commit every 30 seconds.
+  static const int kCommitIntervalMs = 30 * 1000;
+  // Commit right away if we have more than 512 outstanding operations.
+  static const size_t kCommitAfterBatchSize = 512;
+  DCHECK(!background_task_runner_->RunsTasksOnCurrentThread());
+
+  // We do a full copy of the cookie here, and hopefully just here.
+  scoped_ptr<PendingOperation> po(new PendingOperation(op, cc));
+
+  PendingOperationsList::size_type num_pending;
+  {
+    base::AutoLock locked(lock_);
+    pending_.push_back(po.release());
+    num_pending = ++num_pending_;
+  }
+
+  if (num_pending == 1) {
+    // We've gotten our first entry for this batch, fire off the timer.
+    if (!background_task_runner_->PostDelayedTask(
+            FROM_HERE, base::Bind(&Backend::Commit, this),
+            base::TimeDelta::FromMilliseconds(kCommitIntervalMs))) {
+      NOTREACHED() << "background_task_runner_ is not running.";
+    }
+  } else if (num_pending == kCommitAfterBatchSize) {
+    // We've reached a big enough batch, fire off a commit now.
+    PostBackgroundTask(FROM_HERE, base::Bind(&Backend::Commit, this));
+  }
+}
+
+void SQLitePersistentCookieStore::Backend::Commit() {
+  DCHECK(background_task_runner_->RunsTasksOnCurrentThread());
+
+  PendingOperationsList ops;
+  {
+    base::AutoLock locked(lock_);
+    pending_.swap(ops);
+    num_pending_ = 0;
+  }
+
+  // Maybe an old timer fired or we are already Close()'ed.
+  if (!db_.get() || ops.empty())
+    return;
+
+  sql::Statement add_smt(db_->GetCachedStatement(
+      SQL_FROM_HERE,
+      "INSERT INTO cookies (creation_utc, host_key, name, value, "
+      "encrypted_value, path, expires_utc, secure, httponly, firstpartyonly, "
+      "last_access_utc, has_expires, persistent, priority) "
+      "VALUES (?,?,?,?,?,?,?,?,?,?,?,?,?,?)"));
+  if (!add_smt.is_valid())
+    return;
+
+  sql::Statement update_access_smt(db_->GetCachedStatement(SQL_FROM_HERE,
+      "UPDATE cookies SET last_access_utc=? WHERE creation_utc=?"));
+  if (!update_access_smt.is_valid())
+    return;
+
+  sql::Statement del_smt(db_->GetCachedStatement(SQL_FROM_HERE,
+                         "DELETE FROM cookies WHERE creation_utc=?"));
+  if (!del_smt.is_valid())
+    return;
+
+  sql::Transaction transaction(db_.get());
+  if (!transaction.Begin())
+    return;
+
+  for (PendingOperationsList::iterator it = ops.begin();
+       it != ops.end(); ++it) {
+    // Free the cookies as we commit them to the database.
+    scoped_ptr<PendingOperation> po(*it);
+    switch (po->op()) {
+      case PendingOperation::COOKIE_ADD:
+        cookies_per_origin_[
+            CookieOrigin(po->cc().Domain(), po->cc().IsSecure())]++;
+        add_smt.Reset(true);
+        add_smt.BindInt64(0, po->cc().CreationDate().ToInternalValue());
+        add_smt.BindString(1, po->cc().Domain());
+        add_smt.BindString(2, po->cc().Name());
+        if (crypto_) {
+          std::string encrypted_value;
+          add_smt.BindCString(3, "");  // value
+          crypto_->EncryptString(po->cc().Value(), &encrypted_value);
+          // BindBlob() immediately makes an internal copy of the data.
+          add_smt.BindBlob(4, encrypted_value.data(),
+                           static_cast<int>(encrypted_value.length()));
+        } else {
+          add_smt.BindString(3, po->cc().Value());
+          add_smt.BindBlob(4, "", 0);  // encrypted_value
+        }
+        add_smt.BindString(5, po->cc().Path());
+        add_smt.BindInt64(6, po->cc().ExpiryDate().ToInternalValue());
+        add_smt.BindInt(7, po->cc().IsSecure());
+        add_smt.BindInt(8, po->cc().IsHttpOnly());
+        add_smt.BindInt(9, po->cc().IsFirstPartyOnly());
+        add_smt.BindInt64(10, po->cc().LastAccessDate().ToInternalValue());
+        add_smt.BindInt(11, po->cc().IsPersistent());
+        add_smt.BindInt(12, po->cc().IsPersistent());
+        add_smt.BindInt(13,
+                        CookiePriorityToDBCookiePriority(po->cc().Priority()));
+        if (!add_smt.Run())
+          NOTREACHED() << "Could not add a cookie to the DB.";
+        break;
+
+      case PendingOperation::COOKIE_UPDATEACCESS:
+        update_access_smt.Reset(true);
+        update_access_smt.BindInt64(0,
+            po->cc().LastAccessDate().ToInternalValue());
+        update_access_smt.BindInt64(1,
+            po->cc().CreationDate().ToInternalValue());
+        if (!update_access_smt.Run())
+          NOTREACHED() << "Could not update cookie last access time in the DB.";
+        break;
+
+      case PendingOperation::COOKIE_DELETE:
+        cookies_per_origin_[
+            CookieOrigin(po->cc().Domain(), po->cc().IsSecure())]--;
+        del_smt.Reset(true);
+        del_smt.BindInt64(0, po->cc().CreationDate().ToInternalValue());
+        if (!del_smt.Run())
+          NOTREACHED() << "Could not delete a cookie from the DB.";
+        break;
+
+      default:
+        NOTREACHED();
+        break;
+    }
+  }
+  bool succeeded = transaction.Commit();
+  UMA_HISTOGRAM_ENUMERATION("Cookie.BackingStoreUpdateResults",
+                            succeeded ? 0 : 1, 2);
+}
+
+void SQLitePersistentCookieStore::Backend::Flush(
+    const base::Closure& callback) {
+  DCHECK(!background_task_runner_->RunsTasksOnCurrentThread());
+  PostBackgroundTask(FROM_HERE, base::Bind(&Backend::Commit, this));
+
+  if (!callback.is_null()) {
+    // We want the completion task to run immediately after Commit() returns.
+    // Posting it from here means there is less chance of another task getting
+    // onto the message queue first, than if we posted it from Commit() itself.
+    PostBackgroundTask(FROM_HERE, callback);
+  }
+}
+
+// Fire off a close message to the background runner.  We could still have a
+// pending commit timer or Load operations holding references on us, but if/when
+// this fires we will already have been cleaned up and it will be ignored.
+void SQLitePersistentCookieStore::Backend::Close() {
+  if (background_task_runner_->RunsTasksOnCurrentThread()) {
+    InternalBackgroundClose();
+  } else {
+    // Must close the backend on the background runner.
+    PostBackgroundTask(FROM_HERE,
+                       base::Bind(&Backend::InternalBackgroundClose, this));
+  }
+}
+
+void SQLitePersistentCookieStore::Backend::InternalBackgroundClose() {
+  DCHECK(background_task_runner_->RunsTasksOnCurrentThread());
+  // Commit any pending operations
+  Commit();
+
+  if (!force_keep_session_state_ && special_storage_policy_.get() &&
+      special_storage_policy_->HasSessionOnlyOrigins()) {
+    DeleteSessionCookiesOnShutdown();
+  }
+
+  meta_table_.Reset();
+  db_.reset();
+}
+
+void SQLitePersistentCookieStore::Backend::DeleteSessionCookiesOnShutdown() {
+  DCHECK(background_task_runner_->RunsTasksOnCurrentThread());
+
+  if (!db_)
+    return;
+
+  if (!special_storage_policy_.get())
+    return;
+
+  sql::Statement del_smt(db_->GetCachedStatement(
+      SQL_FROM_HERE, "DELETE FROM cookies WHERE host_key=? AND secure=?"));
+  if (!del_smt.is_valid()) {
+    LOG(WARNING) << "Unable to delete cookies on shutdown.";
+    return;
+  }
+
+  sql::Transaction transaction(db_.get());
+  if (!transaction.Begin()) {
+    LOG(WARNING) << "Unable to delete cookies on shutdown.";
+    return;
+  }
+
+  for (CookiesPerOriginMap::iterator it = cookies_per_origin_.begin();
+       it != cookies_per_origin_.end(); ++it) {
+    if (it->second <= 0) {
+      DCHECK_EQ(0, it->second);
+      continue;
+    }
+    const GURL url(net::cookie_util::CookieOriginToURL(it->first.first,
+                                                       it->first.second));
+    if (!url.is_valid() || !special_storage_policy_->IsStorageSessionOnly(url))
+      continue;
+
+    del_smt.Reset(true);
+    del_smt.BindString(0, it->first.first);
+    del_smt.BindInt(1, it->first.second);
+    if (!del_smt.Run())
+      NOTREACHED() << "Could not delete a cookie from the DB.";
+  }
+
+  if (!transaction.Commit())
+    LOG(WARNING) << "Unable to delete cookies on shutdown.";
+}
+
+void SQLitePersistentCookieStore::Backend::DatabaseErrorCallback(
+    int error,
+    sql::Statement* stmt) {
+  DCHECK(background_task_runner_->RunsTasksOnCurrentThread());
+
+  if (!sql::IsErrorCatastrophic(error))
+    return;
+
+  // TODO(shess): Running KillDatabase() multiple times should be
+  // safe.
+  if (corruption_detected_)
+    return;
+
+  corruption_detected_ = true;
+
+  // Don't just do the close/delete here, as we are being called by |db| and
+  // that seems dangerous.
+  // TODO(shess): Consider just calling RazeAndClose() immediately.
+  // db_ may not be safe to reset at this point, but RazeAndClose()
+  // would cause the stack to unwind safely with errors.
+  PostBackgroundTask(FROM_HERE, base::Bind(&Backend::KillDatabase, this));
+}
+
+void SQLitePersistentCookieStore::Backend::KillDatabase() {
+  DCHECK(background_task_runner_->RunsTasksOnCurrentThread());
+
+  if (db_) {
+    // This Backend will now be in-memory only. In a future run we will recreate
+    // the database. Hopefully things go better then!
+    bool success = db_->RazeAndClose();
+    UMA_HISTOGRAM_BOOLEAN("Cookie.KillDatabaseResult", success);
+    meta_table_.Reset();
+    db_.reset();
+  }
+}
+
+void SQLitePersistentCookieStore::Backend::SetForceKeepSessionState() {
+  base::AutoLock locked(lock_);
+  force_keep_session_state_ = true;
+}
+
+void SQLitePersistentCookieStore::Backend::DeleteSessionCookiesOnStartup() {
+  DCHECK(background_task_runner_->RunsTasksOnCurrentThread());
+  base::Time start_time = base::Time::Now();
+  if (!db_->Execute("DELETE FROM cookies WHERE persistent != 1"))
+    LOG(WARNING) << "Unable to delete session cookies.";
+
+  UMA_HISTOGRAM_TIMES("Cookie.Startup.TimeSpentDeletingCookies",
+                      base::Time::Now() - start_time);
+  UMA_HISTOGRAM_COUNTS("Cookie.Startup.NumberOfCookiesDeleted",
+                       db_->GetLastChangeCount());
+}
+
+void SQLitePersistentCookieStore::Backend::PostBackgroundTask(
+    const tracked_objects::Location& origin, const base::Closure& task) {
+  if (!background_task_runner_->PostTask(origin, task)) {
+    LOG(WARNING) << "Failed to post task from " << origin.ToString()
+                 << " to background_task_runner_.";
+  }
+}
+
+void SQLitePersistentCookieStore::Backend::PostClientTask(
+    const tracked_objects::Location& origin, const base::Closure& task) {
+  if (!client_task_runner_->PostTask(origin, task)) {
+    LOG(WARNING) << "Failed to post task from " << origin.ToString()
+                 << " to client_task_runner_.";
+  }
+}
+
+void SQLitePersistentCookieStore::Backend::FinishedLoadingCookies(
+    const LoadedCallback& loaded_callback,
+    bool success) {
+  PostClientTask(FROM_HERE, base::Bind(&Backend::CompleteLoadInForeground, this,
+                                       loaded_callback, success));
+}
+
+SQLitePersistentCookieStore::SQLitePersistentCookieStore(
+    const base::FilePath& path,
+    const scoped_refptr<base::SequencedTaskRunner>& client_task_runner,
+    const scoped_refptr<base::SequencedTaskRunner>& background_task_runner,
+    bool restore_old_session_cookies,
+    storage::SpecialStoragePolicy* special_storage_policy,
+    net::CookieCryptoDelegate* crypto_delegate)
+    : backend_(new Backend(path,
+                           client_task_runner,
+                           background_task_runner,
+                           restore_old_session_cookies,
+                           special_storage_policy,
+                           crypto_delegate)) {
+}
+
+void SQLitePersistentCookieStore::Load(const LoadedCallback& loaded_callback) {
+  backend_->Load(loaded_callback);
+}
+
+void SQLitePersistentCookieStore::LoadCookiesForKey(
+    const std::string& key,
+    const LoadedCallback& loaded_callback) {
+  backend_->LoadCookiesForKey(key, loaded_callback);
+}
+
+void SQLitePersistentCookieStore::AddCookie(const net::CanonicalCookie& cc) {
+  backend_->AddCookie(cc);
+}
+
+void SQLitePersistentCookieStore::UpdateCookieAccessTime(
+    const net::CanonicalCookie& cc) {
+  backend_->UpdateCookieAccessTime(cc);
+}
+
+void SQLitePersistentCookieStore::DeleteCookie(const net::CanonicalCookie& cc) {
+  backend_->DeleteCookie(cc);
+}
+
+void SQLitePersistentCookieStore::SetForceKeepSessionState() {
+  backend_->SetForceKeepSessionState();
+}
+
+void SQLitePersistentCookieStore::Flush(const base::Closure& callback) {
+  backend_->Flush(callback);
+}
+
+SQLitePersistentCookieStore::~SQLitePersistentCookieStore() {
+  backend_->Close();
+  // We release our reference to the Backend, though it will probably still have
+  // a reference if the background runner has not run Close() yet.
+}
+
+CookieStoreConfig::CookieStoreConfig()
+  : session_cookie_mode(EPHEMERAL_SESSION_COOKIES),
+    crypto_delegate(NULL) {
+  // Default to an in-memory cookie store.
+}
+
+CookieStoreConfig::CookieStoreConfig(
+    const base::FilePath& path,
+    SessionCookieMode session_cookie_mode,
+    storage::SpecialStoragePolicy* storage_policy,
+    net::CookieMonsterDelegate* cookie_delegate)
+    : path(path),
+      session_cookie_mode(session_cookie_mode),
+      storage_policy(storage_policy),
+      cookie_delegate(cookie_delegate),
+      crypto_delegate(NULL) {
+  CHECK(!path.empty() || session_cookie_mode == EPHEMERAL_SESSION_COOKIES);
+}
+
+CookieStoreConfig::~CookieStoreConfig() {
+}
+
+net::CookieStore* CreateCookieStore(const CookieStoreConfig& config) {
+  // TODO(bcwhite): Remove ScopedTracker below once crbug.com/483686 is fixed.
+  tracked_objects::ScopedTracker tracking_profile(
+      FROM_HERE_WITH_EXPLICIT_FUNCTION("483686 content::CreateCookieStore"));
+
+  net::CookieMonster* cookie_monster = NULL;
+
+  if (config.path.empty()) {
+    // Empty path means in-memory store.
+    cookie_monster = new net::CookieMonster(NULL, config.cookie_delegate.get());
+  } else {
+    scoped_refptr<base::SequencedTaskRunner> client_task_runner =
+        config.client_task_runner;
+    scoped_refptr<base::SequencedTaskRunner> background_task_runner =
+        config.background_task_runner;
+
+    if (!client_task_runner.get()) {
+      client_task_runner =
+          BrowserThread::GetMessageLoopProxyForThread(BrowserThread::IO);
+    }
+
+    if (!background_task_runner.get()) {
+      background_task_runner =
+          BrowserThread::GetBlockingPool()->GetSequencedTaskRunner(
+              BrowserThread::GetBlockingPool()->GetSequenceToken());
+    }
+
+    SQLitePersistentCookieStore* persistent_store =
+        new SQLitePersistentCookieStore(
+            config.path,
+            client_task_runner,
+            background_task_runner,
+            (config.session_cookie_mode ==
+             CookieStoreConfig::RESTORED_SESSION_COOKIES),
+            config.storage_policy.get(),
+            config.crypto_delegate);
+
+    cookie_monster =
+        new net::CookieMonster(persistent_store, config.cookie_delegate.get());
+    if ((config.session_cookie_mode ==
+         CookieStoreConfig::PERSISTANT_SESSION_COOKIES) ||
+        (config.session_cookie_mode ==
+         CookieStoreConfig::RESTORED_SESSION_COOKIES)) {
+      cookie_monster->SetPersistSessionCookies(true);
+    }
+  }
+
+  return cookie_monster;
+}
+
+}  // namespace content