Moves SQLitePersistentCookieStore to net/extras/sqlite.

The application of special storage policy is split out into a new class,
QuotaPolicyCookieStore, in content/browser/net.

BUG=467596
TEST=No visible impact.

Review URL: https://codereview.chromium.org/1016643004

Cr-Commit-Position: refs/heads/master@{#329950}

4 files changed, 2243 insertions, 0 deletions

diff --git a/net/extras/sqlite/sqlite_persistent_cookie_store.cc b/net/extras/sqlite/sqlite_persistent_cookie_store.cc
new file mode 100644
index 0000000..9fdb070
--- /dev/null
+++ b/net/extras/sqlite/sqlite_persistent_cookie_store.cc
@@ -0,0 +1,1366 @@
+// 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 "net/extras/sqlite/sqlite_persistent_cookie_store.h"
+
+#include <map>
+#include <set>
+
+#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 "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 "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 net {
+
+// 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,
+      CookieCryptoDelegate* crypto_delegate)
+      : path_(path),
+        num_pending_(0),
+        initialized_(false),
+        corruption_detected_(false),
+        restore_old_session_cookies_(restore_old_session_cookies),
+        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 |num_cookies_read_|.
+  void MakeCookiesFromSQLStatement(std::vector<CanonicalCookie*>* cookies,
+                                   sql::Statement* statement);
+
+  // Batch a cookie addition.
+  void AddCookie(const CanonicalCookie& cc);
+
+  // Batch a cookie access time update.
+  void UpdateCookieAccessTime(const CanonicalCookie& cc);
+
+  // Batch a cookie deletion.
+  void DeleteCookie(const 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();
+
+  // Post background delete of all cookies that match |cookies|.
+  void DeleteAllInList(const std::list<CookieOrigin>& cookies);
+
+ 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_EQ(0u, num_pending_);
+    DCHECK(pending_.empty());
+
+    for (CanonicalCookie* cookie : cookies_) {
+      delete cookie;
+    }
+  }
+
+  // Database upgrade statements.
+  bool EnsureDatabaseVersion();
+
+  class PendingOperation {
+   public:
+    enum OperationType {
+      COOKIE_ADD,
+      COOKIE_UPDATEACCESS,
+      COOKIE_DELETE,
+    };
+
+    PendingOperation(OperationType op, const CanonicalCookie& cc)
+        : op_(op), cc_(cc) {}
+
+    OperationType op() const { return op_; }
+    const CanonicalCookie& cc() const { return cc_; }
+
+   private:
+    OperationType op_;
+    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 CanonicalCookie& cc);
+  // Commit our pending operations to the database.
+  void Commit();
+  // Close() executed on the background runner.
+  void InternalBackgroundClose();
+
+  void DeleteSessionCookiesOnStartup();
+
+  void BackgroundDeleteAllInList(const std::list<CookieOrigin>& cookies);
+
+  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);
+
+  const base::FilePath path_;
+  scoped_ptr<sql::Connection> db_;
+  sql::MetaTable meta_table_;
+
+  typedef std::list<PendingOperation*> PendingOperationsList;
+  PendingOperationsList pending_;
+  PendingOperationsList::size_type num_pending_;
+  // Guard |cookies_|, |pending_|, |num_pending_|.
+  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<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_;
+
+  // 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_;
+
+  // 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.
+  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(CookiePriority value) {
+  switch (value) {
+    case COOKIE_PRIORITY_LOW:
+      return kCookiePriorityLow;
+    case COOKIE_PRIORITY_MEDIUM:
+      return kCookiePriorityMedium;
+    case COOKIE_PRIORITY_HIGH:
+      return kCookiePriorityHigh;
+  }
+
+  NOTREACHED();
+  return kCookiePriorityMedium;
+}
+
+CookiePriority DBCookiePriorityToCookiePriority(DBCookiePriority value) {
+  switch (value) {
+    case kCookiePriorityLow:
+      return COOKIE_PRIORITY_LOW;
+    case kCookiePriorityMedium:
+      return COOKIE_PRIORITY_MEDIUM;
+    case kCookiePriorityHigh:
+      return COOKIE_PRIORITY_HIGH;
+  }
+
+  NOTREACHED();
+  return 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(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<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 = registry_controlled_domains::GetDomainAndRegistry(
+        domain, 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<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<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<CanonicalCookie> cc(new 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->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(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 CanonicalCookie& cc) {
+  BatchOperation(PendingOperation::COOKIE_ADD, cc);
+}
+
+void SQLitePersistentCookieStore::Backend::UpdateCookieAccessTime(
+    const CanonicalCookie& cc) {
+  BatchOperation(PendingOperation::COOKIE_UPDATEACCESS, cc);
+}
+
+void SQLitePersistentCookieStore::Backend::DeleteCookie(
+    const CanonicalCookie& cc) {
+  BatchOperation(PendingOperation::COOKIE_DELETE, cc);
+}
+
+void SQLitePersistentCookieStore::Backend::BatchOperation(
+    PendingOperation::OperationType op,
+    const 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:
+        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:
+        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();
+
+  meta_table_.Reset();
+  db_.reset();
+}
+
+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::DeleteAllInList(
+    const std::list<CookieOrigin>& cookies) {
+  if (cookies.empty())
+    return;
+
+  // Perform deletion on background task runner.
+  background_task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(&Backend::BackgroundDeleteAllInList, this, cookies));
+}
+
+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::BackgroundDeleteAllInList(
+    const std::list<CookieOrigin>& cookies) {
+  DCHECK(background_task_runner_->RunsTasksOnCurrentThread());
+
+  if (!db_)
+    return;
+
+  // Force a commit of any pending writes before issuing deletes.
+  // TODO(rohitrao): Remove the need for this Commit() by instead pruning the
+  // list of pending operations. https://crbug.com/486742.
+  Commit();
+
+  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 (const auto& cookie : cookies) {
+    const GURL url(cookie_util::CookieOriginToURL(cookie.first, cookie.second));
+    if (!url.is_valid())
+      continue;
+
+    del_smt.Reset(true);
+    del_smt.BindString(0, cookie.first);
+    del_smt.BindInt(1, cookie.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::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,
+    CookieCryptoDelegate* crypto_delegate)
+    : backend_(new Backend(path,
+                           client_task_runner,
+                           background_task_runner,
+                           restore_old_session_cookies,
+                           crypto_delegate)) {
+}
+
+void SQLitePersistentCookieStore::DeleteAllInList(
+    const std::list<CookieOrigin>& cookies) {
+  backend_->DeleteAllInList(cookies);
+}
+
+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 CanonicalCookie& cc) {
+  backend_->AddCookie(cc);
+}
+
+void SQLitePersistentCookieStore::UpdateCookieAccessTime(
+    const CanonicalCookie& cc) {
+  backend_->UpdateCookieAccessTime(cc);
+}
+
+void SQLitePersistentCookieStore::DeleteCookie(const CanonicalCookie& cc) {
+  backend_->DeleteCookie(cc);
+}
+
+void SQLitePersistentCookieStore::SetForceKeepSessionState() {
+  // This store never discards session-only cookies, so this call has no effect.
+}
+
+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.
+}
+
+}  // namespace net
diff --git a/net/extras/sqlite/sqlite_persistent_cookie_store.h b/net/extras/sqlite/sqlite_persistent_cookie_store.h
new file mode 100644
index 0000000..e29471a
--- /dev/null
+++ b/net/extras/sqlite/sqlite_persistent_cookie_store.h
@@ -0,0 +1,73 @@
+// 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.
+
+#ifndef NET_EXTRAS_SQLITE_SQLITE_PERSISTENT_COOKIE_STORE_H_
+#define NET_EXTRAS_SQLITE_SQLITE_PERSISTENT_COOKIE_STORE_H_
+
+#include <list>
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "base/callback_forward.h"
+#include "base/memory/ref_counted.h"
+#include "net/cookies/cookie_monster.h"
+
+class Task;
+
+namespace base {
+class FilePath;
+class SequencedTaskRunner;
+}  // namespace base
+
+namespace net {
+class CanonicalCookie;
+class CookieCryptoDelegate;
+
+// Implements the PersistentCookieStore interface in terms of a SQLite database.
+// For documentation about the actual member functions consult the documentation
+// of the parent class |CookieMonster::PersistentCookieStore|.
+class SQLitePersistentCookieStore
+    : public CookieMonster::PersistentCookieStore {
+ public:
+  // Contains the origin and a bool indicating whether or not the
+  // origin is secure.
+  typedef std::pair<std::string, bool> CookieOrigin;
+
+  // All blocking database accesses will be performed on
+  // |background_task_runner|, while |client_task_runner| is used to invoke
+  // callbacks.
+  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,
+      CookieCryptoDelegate* crypto_delegate);
+
+  // Deletes the cookies whose origins match those given in |cookies|.
+  void DeleteAllInList(const std::list<CookieOrigin>& cookies);
+
+  // CookieMonster::PersistentCookieStore:
+  void Load(const LoadedCallback& loaded_callback) override;
+  void LoadCookiesForKey(const std::string& key,
+                         const LoadedCallback& callback) override;
+  void AddCookie(const CanonicalCookie& cc) override;
+  void UpdateCookieAccessTime(const CanonicalCookie& cc) override;
+  void DeleteCookie(const CanonicalCookie& cc) override;
+  void SetForceKeepSessionState() override;
+  void Flush(const base::Closure& callback) override;
+
+ private:
+  ~SQLitePersistentCookieStore() override;
+
+  class Backend;
+
+  scoped_refptr<Backend> backend_;
+
+  DISALLOW_COPY_AND_ASSIGN(SQLitePersistentCookieStore);
+};
+
+}  // namespace net
+
+#endif  // NET_EXTRAS_SQLITE_SQLITE_PERSISTENT_COOKIE_STORE_H_
diff --git a/net/extras/sqlite/sqlite_persistent_cookie_store_perftest.cc b/net/extras/sqlite/sqlite_persistent_cookie_store_perftest.cc
new file mode 100644
index 0000000..b149ac0
--- /dev/null
+++ b/net/extras/sqlite/sqlite_persistent_cookie_store_perftest.cc
@@ -0,0 +1,141 @@
+// 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 "net/extras/sqlite/sqlite_persistent_cookie_store.h"
+
+#include <vector>
+
+#include "base/bind.h"
+#include "base/compiler_specific.h"
+#include "base/files/scoped_temp_dir.h"
+#include "base/message_loop/message_loop.h"
+#include "base/sequenced_task_runner.h"
+#include "base/strings/stringprintf.h"
+#include "base/synchronization/waitable_event.h"
+#include "base/test/perf_time_logger.h"
+#include "base/test/sequenced_worker_pool_owner.h"
+#include "base/threading/sequenced_worker_pool.h"
+#include "net/cookies/canonical_cookie.h"
+#include "net/cookies/cookie_constants.h"
+#include "net/extras/sqlite/cookie_crypto_delegate.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "url/gurl.h"
+
+namespace net {
+
+namespace {
+
+const base::FilePath::CharType cookie_filename[] = FILE_PATH_LITERAL("Cookies");
+
+}  // namespace
+
+class SQLitePersistentCookieStorePerfTest : public testing::Test {
+ public:
+  SQLitePersistentCookieStorePerfTest()
+      : pool_owner_(new base::SequencedWorkerPoolOwner(1, "Background Pool")),
+        loaded_event_(false, false),
+        key_loaded_event_(false, false) {}
+
+  void OnLoaded(const std::vector<CanonicalCookie*>& cookies) {
+    cookies_ = cookies;
+    loaded_event_.Signal();
+  }
+
+  void OnKeyLoaded(const std::vector<CanonicalCookie*>& cookies) {
+    cookies_ = cookies;
+    key_loaded_event_.Signal();
+  }
+
+  void Load() {
+    store_->Load(base::Bind(&SQLitePersistentCookieStorePerfTest::OnLoaded,
+                            base::Unretained(this)));
+    loaded_event_.Wait();
+  }
+
+  scoped_refptr<base::SequencedTaskRunner> background_task_runner() {
+    return pool_owner_->pool()->GetSequencedTaskRunner(
+        pool_owner_->pool()->GetNamedSequenceToken("background"));
+  }
+
+  scoped_refptr<base::SequencedTaskRunner> client_task_runner() {
+    return pool_owner_->pool()->GetSequencedTaskRunner(
+        pool_owner_->pool()->GetNamedSequenceToken("client"));
+  }
+
+  void SetUp() override {
+    ASSERT_TRUE(temp_dir_.CreateUniqueTempDir());
+    store_ = new SQLitePersistentCookieStore(
+        temp_dir_.path().Append(cookie_filename), client_task_runner(),
+        background_task_runner(), false, NULL);
+    std::vector<CanonicalCookie*> cookies;
+    Load();
+    ASSERT_EQ(0u, cookies_.size());
+    // Creates 15000 cookies from 300 eTLD+1s.
+    base::Time t = base::Time::Now();
+    for (int domain_num = 0; domain_num < 300; domain_num++) {
+      std::string domain_name(base::StringPrintf(".domain_%d.com", domain_num));
+      GURL gurl("www" + domain_name);
+      for (int cookie_num = 0; cookie_num < 50; ++cookie_num) {
+        t += base::TimeDelta::FromInternalValue(10);
+        store_->AddCookie(CanonicalCookie(
+            gurl, base::StringPrintf("Cookie_%d", cookie_num), "1", domain_name,
+            "/", t, t, t, false, false, false, COOKIE_PRIORITY_DEFAULT));
+      }
+    }
+    // Replace the store effectively destroying the current one and forcing it
+    // to write its data to disk.
+    store_ = NULL;
+
+    // Shut down the pool, causing deferred (no-op) commits to be discarded.
+    pool_owner_->pool()->Shutdown();
+    // ~SequencedWorkerPoolOwner blocks on pool shutdown.
+    pool_owner_.reset(new base::SequencedWorkerPoolOwner(1, "pool"));
+
+    store_ = new SQLitePersistentCookieStore(
+        temp_dir_.path().Append(cookie_filename), client_task_runner(),
+        background_task_runner(), false, NULL);
+  }
+
+  void TearDown() override {
+    store_ = NULL;
+    pool_owner_->pool()->Shutdown();
+  }
+
+ protected:
+  base::MessageLoop main_loop_;
+  scoped_ptr<base::SequencedWorkerPoolOwner> pool_owner_;
+  base::WaitableEvent loaded_event_;
+  base::WaitableEvent key_loaded_event_;
+  std::vector<CanonicalCookie*> cookies_;
+  base::ScopedTempDir temp_dir_;
+  scoped_refptr<SQLitePersistentCookieStore> store_;
+};
+
+// Test the performance of priority load of cookies for a specfic domain key
+TEST_F(SQLitePersistentCookieStorePerfTest, TestLoadForKeyPerformance) {
+  for (int domain_num = 0; domain_num < 3; ++domain_num) {
+    std::string domain_name(base::StringPrintf("domain_%d.com", domain_num));
+    base::PerfTimeLogger timer(
+        ("Load cookies for the eTLD+1 " + domain_name).c_str());
+    store_->LoadCookiesForKey(
+        domain_name,
+        base::Bind(&SQLitePersistentCookieStorePerfTest::OnKeyLoaded,
+                   base::Unretained(this)));
+    key_loaded_event_.Wait();
+    timer.Done();
+
+    ASSERT_EQ(50U, cookies_.size());
+  }
+}
+
+// Test the performance of load
+TEST_F(SQLitePersistentCookieStorePerfTest, TestLoadPerformance) {
+  base::PerfTimeLogger timer("Load all cookies");
+  Load();
+  timer.Done();
+
+  ASSERT_EQ(15000U, cookies_.size());
+}
+
+}  // namespace net
diff --git a/net/extras/sqlite/sqlite_persistent_cookie_store_unittest.cc b/net/extras/sqlite/sqlite_persistent_cookie_store_unittest.cc
new file mode 100644
index 0000000..6dc3810
--- /dev/null
+++ b/net/extras/sqlite/sqlite_persistent_cookie_store_unittest.cc
@@ -0,0 +1,663 @@
+// 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 "net/extras/sqlite/sqlite_persistent_cookie_store.h"
+
+#include <map>
+#include <set>
+
+#include "base/bind.h"
+#include "base/callback.h"
+#include "base/files/file_util.h"
+#include "base/files/scoped_temp_dir.h"
+#include "base/location.h"
+#include "base/memory/ref_counted.h"
+#include "base/sequenced_task_runner.h"
+#include "base/stl_util.h"
+#include "base/synchronization/waitable_event.h"
+#include "base/test/sequenced_worker_pool_owner.h"
+#include "base/threading/sequenced_worker_pool.h"
+#include "base/time/time.h"
+#include "crypto/encryptor.h"
+#include "crypto/symmetric_key.h"
+#include "net/cookies/canonical_cookie.h"
+#include "net/cookies/cookie_constants.h"
+#include "net/extras/sqlite/cookie_crypto_delegate.h"
+#include "sql/connection.h"
+#include "sql/meta_table.h"
+#include "sql/statement.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "url/gurl.h"
+
+namespace net {
+
+namespace {
+
+const base::FilePath::CharType kCookieFilename[] = FILE_PATH_LITERAL("Cookies");
+
+class CookieCryptor : public CookieCryptoDelegate {
+ public:
+  CookieCryptor();
+  bool EncryptString(const std::string& plaintext,
+                     std::string* ciphertext) override;
+  bool DecryptString(const std::string& ciphertext,
+                     std::string* plaintext) override;
+
+ private:
+  scoped_ptr<crypto::SymmetricKey> key_;
+  crypto::Encryptor encryptor_;
+};
+
+CookieCryptor::CookieCryptor()
+    : key_(
+          crypto::SymmetricKey::DeriveKeyFromPassword(crypto::SymmetricKey::AES,
+                                                      "password",
+                                                      "saltiest",
+                                                      1000,
+                                                      256)) {
+  std::string iv("the iv: 16 bytes");
+  encryptor_.Init(key_.get(), crypto::Encryptor::CBC, iv);
+}
+
+bool CookieCryptor::EncryptString(const std::string& plaintext,
+                                  std::string* ciphertext) {
+  return encryptor_.Encrypt(plaintext, ciphertext);
+}
+
+bool CookieCryptor::DecryptString(const std::string& ciphertext,
+                                  std::string* plaintext) {
+  return encryptor_.Decrypt(ciphertext, plaintext);
+}
+
+}  // namespace
+
+typedef std::vector<CanonicalCookie*> CanonicalCookieVector;
+
+class SQLitePersistentCookieStoreTest : public testing::Test {
+ public:
+  SQLitePersistentCookieStoreTest()
+      : pool_owner_(new base::SequencedWorkerPoolOwner(3, "Background Pool")),
+        loaded_event_(false, false),
+        key_loaded_event_(false, false),
+        db_thread_event_(false, false) {}
+
+  void OnLoaded(const CanonicalCookieVector& cookies) {
+    cookies_ = cookies;
+    loaded_event_.Signal();
+  }
+
+  void OnKeyLoaded(const CanonicalCookieVector& cookies) {
+    cookies_ = cookies;
+    key_loaded_event_.Signal();
+  }
+
+  void Load(CanonicalCookieVector* cookies) {
+    EXPECT_FALSE(loaded_event_.IsSignaled());
+    store_->Load(base::Bind(&SQLitePersistentCookieStoreTest::OnLoaded,
+                            base::Unretained(this)));
+    loaded_event_.Wait();
+    *cookies = cookies_;
+  }
+
+  void Flush() {
+    base::WaitableEvent event(false, false);
+    store_->Flush(
+        base::Bind(&base::WaitableEvent::Signal, base::Unretained(&event)));
+    event.Wait();
+  }
+
+  scoped_refptr<base::SequencedTaskRunner> background_task_runner() {
+    return pool_owner_->pool()->GetSequencedTaskRunner(
+        pool_owner_->pool()->GetNamedSequenceToken("background"));
+  }
+
+  scoped_refptr<base::SequencedTaskRunner> client_task_runner() {
+    return pool_owner_->pool()->GetSequencedTaskRunner(
+        pool_owner_->pool()->GetNamedSequenceToken("client"));
+  }
+
+  void DestroyStore() {
+    store_ = nullptr;
+    // Make sure we wait until the destructor has run by shutting down the pool
+    // resetting the owner (whose destructor blocks on the pool completion).
+    pool_owner_->pool()->Shutdown();
+    // Create a new pool for the few tests that create multiple stores. In other
+    // cases this is wasted but harmless.
+    pool_owner_.reset(new base::SequencedWorkerPoolOwner(3, "Background Pool"));
+  }
+
+  void CreateAndLoad(bool crypt_cookies,
+                     bool restore_old_session_cookies,
+                     CanonicalCookieVector* cookies) {
+    if (crypt_cookies)
+      cookie_crypto_delegate_.reset(new CookieCryptor());
+
+    store_ = new SQLitePersistentCookieStore(
+        temp_dir_.path().Append(kCookieFilename), client_task_runner(),
+        background_task_runner(), restore_old_session_cookies,
+        cookie_crypto_delegate_.get());
+    Load(cookies);
+  }
+
+  void InitializeStore(bool crypt, bool restore_old_session_cookies) {
+    CanonicalCookieVector cookies;
+    CreateAndLoad(crypt, restore_old_session_cookies, &cookies);
+    EXPECT_EQ(0U, cookies.size());
+  }
+
+  // We have to create this method to wrap WaitableEvent::Wait, since we cannot
+  // bind a non-void returning method as a Closure.
+  void WaitOnDBEvent() { db_thread_event_.Wait(); }
+
+  // Adds a persistent cookie to store_.
+  void AddCookie(const std::string& name,
+                 const std::string& value,
+                 const std::string& domain,
+                 const std::string& path,
+                 const base::Time& creation) {
+    store_->AddCookie(CanonicalCookie(GURL(), name, value, domain, path,
+                                      creation, creation, creation, false,
+                                      false, false, COOKIE_PRIORITY_DEFAULT));
+  }
+
+  void AddCookieWithExpiration(const std::string& name,
+                               const std::string& value,
+                               const std::string& domain,
+                               const std::string& path,
+                               const base::Time& creation,
+                               const base::Time& expiration) {
+    store_->AddCookie(CanonicalCookie(GURL(), name, value, domain, path,
+                                      creation, expiration, creation, false,
+                                      false, false, COOKIE_PRIORITY_DEFAULT));
+  }
+
+  std::string ReadRawDBContents() {
+    std::string contents;
+    if (!base::ReadFileToString(temp_dir_.path().Append(kCookieFilename),
+                                &contents))
+      return std::string();
+    return contents;
+  }
+
+  void SetUp() override { ASSERT_TRUE(temp_dir_.CreateUniqueTempDir()); }
+
+  void TearDown() override {
+    DestroyStore();
+    pool_owner_->pool()->Shutdown();
+  }
+
+ protected:
+  scoped_ptr<base::SequencedWorkerPoolOwner> pool_owner_;
+  base::WaitableEvent loaded_event_;
+  base::WaitableEvent key_loaded_event_;
+  base::WaitableEvent db_thread_event_;
+  CanonicalCookieVector cookies_;
+  base::ScopedTempDir temp_dir_;
+  scoped_refptr<SQLitePersistentCookieStore> store_;
+  scoped_ptr<CookieCryptoDelegate> cookie_crypto_delegate_;
+};
+
+TEST_F(SQLitePersistentCookieStoreTest, TestInvalidMetaTableRecovery) {
+  InitializeStore(false, false);
+  AddCookie("A", "B", "foo.bar", "/", base::Time::Now());
+  DestroyStore();
+
+  // Load up the store and verify that it has good data in it.
+  CanonicalCookieVector cookies;
+  CreateAndLoad(false, false, &cookies);
+  ASSERT_EQ(1U, cookies.size());
+  ASSERT_STREQ("foo.bar", cookies[0]->Domain().c_str());
+  ASSERT_STREQ("A", cookies[0]->Name().c_str());
+  ASSERT_STREQ("B", cookies[0]->Value().c_str());
+  DestroyStore();
+  STLDeleteElements(&cookies);
+
+  // Now corrupt the meta table.
+  {
+    sql::Connection db;
+    ASSERT_TRUE(db.Open(temp_dir_.path().Append(kCookieFilename)));
+    sql::MetaTable meta_table_;
+    meta_table_.Init(&db, 1, 1);
+    ASSERT_TRUE(db.Execute("DELETE FROM meta"));
+    db.Close();
+  }
+
+  // Upon loading, the database should be reset to a good, blank state.
+  CreateAndLoad(false, false, &cookies);
+  ASSERT_EQ(0U, cookies.size());
+
+  // Verify that, after, recovery, the database persists properly.
+  AddCookie("X", "Y", "foo.bar", "/", base::Time::Now());
+  DestroyStore();
+  CreateAndLoad(false, false, &cookies);
+  ASSERT_EQ(1U, cookies.size());
+  ASSERT_STREQ("foo.bar", cookies[0]->Domain().c_str());
+  ASSERT_STREQ("X", cookies[0]->Name().c_str());
+  ASSERT_STREQ("Y", cookies[0]->Value().c_str());
+  STLDeleteElements(&cookies);
+}
+
+// Test if data is stored as expected in the SQLite database.
+TEST_F(SQLitePersistentCookieStoreTest, TestPersistance) {
+  InitializeStore(false, false);
+  AddCookie("A", "B", "foo.bar", "/", base::Time::Now());
+  // Replace the store effectively destroying the current one and forcing it
+  // to write its data to disk. Then we can see if after loading it again it
+  // is still there.
+  DestroyStore();
+  // Reload and test for persistence
+  CanonicalCookieVector cookies;
+  CreateAndLoad(false, false, &cookies);
+  ASSERT_EQ(1U, cookies.size());
+  ASSERT_STREQ("foo.bar", cookies[0]->Domain().c_str());
+  ASSERT_STREQ("A", cookies[0]->Name().c_str());
+  ASSERT_STREQ("B", cookies[0]->Value().c_str());
+
+  // Now delete the cookie and check persistence again.
+  store_->DeleteCookie(*cookies[0]);
+  DestroyStore();
+  STLDeleteElements(&cookies);
+
+  // Reload and check if the cookie has been removed.
+  CreateAndLoad(false, false, &cookies);
+  ASSERT_EQ(0U, cookies.size());
+}
+
+TEST_F(SQLitePersistentCookieStoreTest, TestSessionCookiesDeletedOnStartup) {
+  // Initialize the cookie store with 3 persistent cookies, 5 transient
+  // cookies.
+  InitializeStore(false, false);
+
+  // Add persistent cookies.
+  base::Time t = base::Time::Now();
+  AddCookie("A", "B", "a1.com", "/", t);
+  t += base::TimeDelta::FromInternalValue(10);
+  AddCookie("A", "B", "a2.com", "/", t);
+  t += base::TimeDelta::FromInternalValue(10);
+  AddCookie("A", "B", "a3.com", "/", t);
+
+  // Add transient cookies.
+  t += base::TimeDelta::FromInternalValue(10);
+  AddCookieWithExpiration("A", "B", "b1.com", "/", t, base::Time());
+  t += base::TimeDelta::FromInternalValue(10);
+  AddCookieWithExpiration("A", "B", "b2.com", "/", t, base::Time());
+  t += base::TimeDelta::FromInternalValue(10);
+  AddCookieWithExpiration("A", "B", "b3.com", "/", t, base::Time());
+  t += base::TimeDelta::FromInternalValue(10);
+  AddCookieWithExpiration("A", "B", "b4.com", "/", t, base::Time());
+  t += base::TimeDelta::FromInternalValue(10);
+  AddCookieWithExpiration("A", "B", "b5.com", "/", t, base::Time());
+  DestroyStore();
+
+  // Load the store a second time. Before the store finishes loading, add a
+  // transient cookie and flush it to disk.
+  store_ = new SQLitePersistentCookieStore(
+      temp_dir_.path().Append(kCookieFilename), client_task_runner(),
+      background_task_runner(), false, nullptr);
+
+  // Posting a blocking task to db_thread_ makes sure that the DB thread waits
+  // until both Load and Flush have been posted to its task queue.
+  background_task_runner()->PostTask(
+      FROM_HERE, base::Bind(&SQLitePersistentCookieStoreTest::WaitOnDBEvent,
+                            base::Unretained(this)));
+  store_->Load(base::Bind(&SQLitePersistentCookieStoreTest::OnLoaded,
+                          base::Unretained(this)));
+  t += base::TimeDelta::FromInternalValue(10);
+  AddCookieWithExpiration("A", "B", "c.com", "/", t, base::Time());
+  base::WaitableEvent event(false, false);
+  store_->Flush(
+      base::Bind(&base::WaitableEvent::Signal, base::Unretained(&event)));
+
+  // Now the DB-thread queue contains:
+  // (active:)
+  // 1. Wait (on db_event)
+  // (pending:)
+  // 2. "Init And Chain-Load First Domain"
+  // 3. Add Cookie (c.com)
+  // 4. Flush Cookie (c.com)
+  db_thread_event_.Signal();
+  event.Wait();
+  loaded_event_.Wait();
+  STLDeleteElements(&cookies_);
+  DestroyStore();
+
+  // Load the store a third time, this time restoring session cookies. The
+  // store should contain exactly 4 cookies: the 3 persistent, and "c.com",
+  // which was added during the second cookie store load.
+  store_ = new SQLitePersistentCookieStore(
+      temp_dir_.path().Append(kCookieFilename), client_task_runner(),
+      background_task_runner(), true, nullptr);
+  store_->Load(base::Bind(&SQLitePersistentCookieStoreTest::OnLoaded,
+                          base::Unretained(this)));
+  loaded_event_.Wait();
+  ASSERT_EQ(4u, cookies_.size());
+  STLDeleteElements(&cookies_);
+}
+
+// Test that priority load of cookies for a specfic domain key could be
+// completed before the entire store is loaded
+TEST_F(SQLitePersistentCookieStoreTest, TestLoadCookiesForKey) {
+  InitializeStore(false, false);
+  base::Time t = base::Time::Now();
+  AddCookie("A", "B", "foo.bar", "/", t);
+  t += base::TimeDelta::FromInternalValue(10);
+  AddCookie("A", "B", "www.aaa.com", "/", t);
+  t += base::TimeDelta::FromInternalValue(10);
+  AddCookie("A", "B", "travel.aaa.com", "/", t);
+  t += base::TimeDelta::FromInternalValue(10);
+  AddCookie("A", "B", "www.bbb.com", "/", t);
+  DestroyStore();
+
+  store_ = new SQLitePersistentCookieStore(
+      temp_dir_.path().Append(kCookieFilename), client_task_runner(),
+      background_task_runner(), false, nullptr);
+
+  // Posting a blocking task to db_thread_ makes sure that the DB thread waits
+  // until both Load and LoadCookiesForKey have been posted to its task queue.
+  background_task_runner()->PostTask(
+      FROM_HERE, base::Bind(&SQLitePersistentCookieStoreTest::WaitOnDBEvent,
+                            base::Unretained(this)));
+  store_->Load(base::Bind(&SQLitePersistentCookieStoreTest::OnLoaded,
+                          base::Unretained(this)));
+  store_->LoadCookiesForKey(
+      "aaa.com", base::Bind(&SQLitePersistentCookieStoreTest::OnKeyLoaded,
+                            base::Unretained(this)));
+  background_task_runner()->PostTask(
+      FROM_HERE, base::Bind(&SQLitePersistentCookieStoreTest::WaitOnDBEvent,
+                            base::Unretained(this)));
+
+  // Now the DB-thread queue contains:
+  // (active:)
+  // 1. Wait (on db_event)
+  // (pending:)
+  // 2. "Init And Chain-Load First Domain"
+  // 3. Priority Load (aaa.com)
+  // 4. Wait (on db_event)
+  db_thread_event_.Signal();
+  key_loaded_event_.Wait();
+  ASSERT_EQ(loaded_event_.IsSignaled(), false);
+  std::set<std::string> cookies_loaded;
+  for (CanonicalCookieVector::const_iterator it = cookies_.begin();
+       it != cookies_.end(); ++it) {
+    cookies_loaded.insert((*it)->Domain().c_str());
+  }
+  STLDeleteElements(&cookies_);
+  ASSERT_GT(4U, cookies_loaded.size());
+  ASSERT_EQ(true, cookies_loaded.find("www.aaa.com") != cookies_loaded.end());
+  ASSERT_EQ(true,
+            cookies_loaded.find("travel.aaa.com") != cookies_loaded.end());
+
+  db_thread_event_.Signal();
+  loaded_event_.Wait();
+  for (CanonicalCookieVector::const_iterator it = cookies_.begin();
+       it != cookies_.end(); ++it) {
+    cookies_loaded.insert((*it)->Domain().c_str());
+  }
+  ASSERT_EQ(4U, cookies_loaded.size());
+  ASSERT_EQ(cookies_loaded.find("foo.bar") != cookies_loaded.end(), true);
+  ASSERT_EQ(cookies_loaded.find("www.bbb.com") != cookies_loaded.end(), true);
+  STLDeleteElements(&cookies_);
+}
+
+// Test that we can force the database to be written by calling Flush().
+TEST_F(SQLitePersistentCookieStoreTest, TestFlush) {
+  InitializeStore(false, false);
+  // File timestamps don't work well on all platforms, so we'll determine
+  // whether the DB file has been modified by checking its size.
+  base::FilePath path = temp_dir_.path().Append(kCookieFilename);
+  base::File::Info info;
+  ASSERT_TRUE(base::GetFileInfo(path, &info));
+  int64 base_size = info.size;
+
+  // Write some large cookies, so the DB will have to expand by several KB.
+  for (char c = 'a'; c < 'z'; ++c) {
+    // Each cookie needs a unique timestamp for creation_utc (see DB schema).
+    base::Time t = base::Time::Now() + base::TimeDelta::FromMicroseconds(c);
+    std::string name(1, c);
+    std::string value(1000, c);
+    AddCookie(name, value, "foo.bar", "/", t);
+  }
+
+  Flush();
+
+  // We forced a write, so now the file will be bigger.
+  ASSERT_TRUE(base::GetFileInfo(path, &info));
+  ASSERT_GT(info.size, base_size);
+}
+
+// Test loading old session cookies from the disk.
+TEST_F(SQLitePersistentCookieStoreTest, TestLoadOldSessionCookies) {
+  InitializeStore(false, true);
+
+  // Add a session cookie.
+  store_->AddCookie(CanonicalCookie(GURL(), "C", "D", "sessioncookie.com", "/",
+                                    base::Time::Now(), base::Time(),
+                                    base::Time::Now(), false, false, false,
+                                    COOKIE_PRIORITY_DEFAULT));
+
+  // Force the store to write its data to the disk.
+  DestroyStore();
+
+  // Create a store that loads session cookies and test that the session cookie
+  // was loaded.
+  CanonicalCookieVector cookies;
+  CreateAndLoad(false, true, &cookies);
+
+  ASSERT_EQ(1U, cookies.size());
+  ASSERT_STREQ("sessioncookie.com", cookies[0]->Domain().c_str());
+  ASSERT_STREQ("C", cookies[0]->Name().c_str());
+  ASSERT_STREQ("D", cookies[0]->Value().c_str());
+  ASSERT_EQ(COOKIE_PRIORITY_DEFAULT, cookies[0]->Priority());
+
+  STLDeleteElements(&cookies);
+}
+
+// Test loading old session cookies from the disk.
+TEST_F(SQLitePersistentCookieStoreTest, TestDontLoadOldSessionCookies) {
+  InitializeStore(false, true);
+
+  // Add a session cookie.
+  store_->AddCookie(CanonicalCookie(GURL(), "C", "D", "sessioncookie.com", "/",
+                                    base::Time::Now(), base::Time(),
+                                    base::Time::Now(), false, false, false,
+                                    COOKIE_PRIORITY_DEFAULT));
+
+  // Force the store to write its data to the disk.
+  DestroyStore();
+
+  // Create a store that doesn't load old session cookies and test that the
+  // session cookie was not loaded.
+  CanonicalCookieVector cookies;
+  CreateAndLoad(false, false, &cookies);
+  ASSERT_EQ(0U, cookies.size());
+
+  // The store should also delete the session cookie. Wait until that has been
+  // done.
+  DestroyStore();
+
+  // Create a store that loads old session cookies and test that the session
+  // cookie is gone.
+  CreateAndLoad(false, true, &cookies);
+  ASSERT_EQ(0U, cookies.size());
+}
+
+TEST_F(SQLitePersistentCookieStoreTest, PersistIsPersistent) {
+  InitializeStore(false, true);
+  static const char kSessionName[] = "session";
+  static const char kPersistentName[] = "persistent";
+
+  // Add a session cookie.
+  store_->AddCookie(CanonicalCookie(GURL(), kSessionName, "val",
+                                    "sessioncookie.com", "/", base::Time::Now(),
+                                    base::Time(), base::Time::Now(), false,
+                                    false, false, COOKIE_PRIORITY_DEFAULT));
+  // Add a persistent cookie.
+  store_->AddCookie(CanonicalCookie(
+      GURL(), kPersistentName, "val", "sessioncookie.com", "/",
+      base::Time::Now() - base::TimeDelta::FromDays(1),
+      base::Time::Now() + base::TimeDelta::FromDays(1), base::Time::Now(),
+      false, false, false, COOKIE_PRIORITY_DEFAULT));
+
+  // Force the store to write its data to the disk.
+  DestroyStore();
+
+  // Create a store that loads session cookie and test that the IsPersistent
+  // attribute is restored.
+  CanonicalCookieVector cookies;
+  CreateAndLoad(false, true, &cookies);
+  ASSERT_EQ(2U, cookies.size());
+
+  std::map<std::string, CanonicalCookie*> cookie_map;
+  for (CanonicalCookieVector::const_iterator it = cookies.begin();
+       it != cookies.end(); ++it) {
+    cookie_map[(*it)->Name()] = *it;
+  }
+
+  std::map<std::string, CanonicalCookie*>::const_iterator it =
+      cookie_map.find(kSessionName);
+  ASSERT_TRUE(it != cookie_map.end());
+  EXPECT_FALSE(cookie_map[kSessionName]->IsPersistent());
+
+  it = cookie_map.find(kPersistentName);
+  ASSERT_TRUE(it != cookie_map.end());
+  EXPECT_TRUE(cookie_map[kPersistentName]->IsPersistent());
+
+  STLDeleteElements(&cookies);
+}
+
+TEST_F(SQLitePersistentCookieStoreTest, PriorityIsPersistent) {
+  static const char kLowName[] = "low";
+  static const char kMediumName[] = "medium";
+  static const char kHighName[] = "high";
+  static const char kCookieDomain[] = "sessioncookie.com";
+  static const char kCookieValue[] = "value";
+  static const char kCookiePath[] = "/";
+
+  InitializeStore(false, true);
+
+  // Add a low-priority persistent cookie.
+  store_->AddCookie(CanonicalCookie(
+      GURL(), kLowName, kCookieValue, kCookieDomain, kCookiePath,
+      base::Time::Now() - base::TimeDelta::FromMinutes(1),
+      base::Time::Now() + base::TimeDelta::FromDays(1), base::Time::Now(),
+      false, false, false, COOKIE_PRIORITY_LOW));
+
+  // Add a medium-priority persistent cookie.
+  store_->AddCookie(CanonicalCookie(
+      GURL(), kMediumName, kCookieValue, kCookieDomain, kCookiePath,
+      base::Time::Now() - base::TimeDelta::FromMinutes(2),
+      base::Time::Now() + base::TimeDelta::FromDays(1), base::Time::Now(),
+      false, false, false, COOKIE_PRIORITY_MEDIUM));
+
+  // Add a high-priority peristent cookie.
+  store_->AddCookie(CanonicalCookie(
+      GURL(), kHighName, kCookieValue, kCookieDomain, kCookiePath,
+      base::Time::Now() - base::TimeDelta::FromMinutes(3),
+      base::Time::Now() + base::TimeDelta::FromDays(1), base::Time::Now(),
+      false, false, false, COOKIE_PRIORITY_HIGH));
+
+  // Force the store to write its data to the disk.
+  DestroyStore();
+
+  // Create a store that loads session cookie and test that the priority
+  // attribute values are restored.
+  CanonicalCookieVector cookies;
+  CreateAndLoad(false, true, &cookies);
+  ASSERT_EQ(3U, cookies.size());
+
+  // Put the cookies into a map, by name, so we can easily find them.
+  std::map<std::string, CanonicalCookie*> cookie_map;
+  for (CanonicalCookieVector::const_iterator it = cookies.begin();
+       it != cookies.end(); ++it) {
+    cookie_map[(*it)->Name()] = *it;
+  }
+
+  // Validate that each cookie has the correct priority.
+  std::map<std::string, CanonicalCookie*>::const_iterator it =
+      cookie_map.find(kLowName);
+  ASSERT_TRUE(it != cookie_map.end());
+  EXPECT_EQ(COOKIE_PRIORITY_LOW, cookie_map[kLowName]->Priority());
+
+  it = cookie_map.find(kMediumName);
+  ASSERT_TRUE(it != cookie_map.end());
+  EXPECT_EQ(COOKIE_PRIORITY_MEDIUM, cookie_map[kMediumName]->Priority());
+
+  it = cookie_map.find(kHighName);
+  ASSERT_TRUE(it != cookie_map.end());
+  EXPECT_EQ(COOKIE_PRIORITY_HIGH, cookie_map[kHighName]->Priority());
+
+  STLDeleteElements(&cookies);
+}
+
+TEST_F(SQLitePersistentCookieStoreTest, UpdateToEncryption) {
+  CanonicalCookieVector cookies;
+
+  // Create unencrypted cookie store and write something to it.
+  InitializeStore(false, false);
+  AddCookie("name", "value123XYZ", "foo.bar", "/", base::Time::Now());
+  DestroyStore();
+
+  // Verify that "value" is visible in the file.  This is necessary in order to
+  // have confidence in a later test that "encrypted_value" is not visible.
+  std::string contents = ReadRawDBContents();
+  EXPECT_NE(0U, contents.length());
+  EXPECT_NE(contents.find("value123XYZ"), std::string::npos);
+
+  // Create encrypted cookie store and ensure old cookie still reads.
+  STLDeleteElements(&cookies_);
+  EXPECT_EQ(0U, cookies_.size());
+  CreateAndLoad(true, false, &cookies);
+  EXPECT_EQ(1U, cookies_.size());
+  EXPECT_EQ("name", cookies_[0]->Name());
+  EXPECT_EQ("value123XYZ", cookies_[0]->Value());
+
+  // Make sure we can update existing cookie and add new cookie as encrypted.
+  store_->DeleteCookie(*(cookies_[0]));
+  AddCookie("name", "encrypted_value123XYZ", "foo.bar", "/", base::Time::Now());
+  AddCookie("other", "something456ABC", "foo.bar", "/",
+            base::Time::Now() + base::TimeDelta::FromInternalValue(10));
+  DestroyStore();
+  STLDeleteElements(&cookies_);
+  CreateAndLoad(true, false, &cookies);
+  EXPECT_EQ(2U, cookies_.size());
+  CanonicalCookie* cookie_name = nullptr;
+  CanonicalCookie* cookie_other = nullptr;
+  if (cookies_[0]->Name() == "name") {
+    cookie_name = cookies_[0];
+    cookie_other = cookies_[1];
+  } else {
+    cookie_name = cookies_[1];
+    cookie_other = cookies_[0];
+  }
+  EXPECT_EQ("encrypted_value123XYZ", cookie_name->Value());
+  EXPECT_EQ("something456ABC", cookie_other->Value());
+  DestroyStore();
+  STLDeleteElements(&cookies_);
+
+  // Examine the real record to make sure plaintext version doesn't exist.
+  sql::Connection db;
+  sql::Statement smt;
+  int resultcount = 0;
+  ASSERT_TRUE(db.Open(temp_dir_.path().Append(kCookieFilename)));
+  smt.Assign(db.GetCachedStatement(SQL_FROM_HERE,
+                                   "SELECT * "
+                                   "FROM cookies "
+                                   "WHERE host_key = 'foo.bar'"));
+  while (smt.Step()) {
+    resultcount++;
+    for (int i = 0; i < smt.ColumnCount(); i++) {
+      EXPECT_EQ(smt.ColumnString(i).find("value"), std::string::npos);
+      EXPECT_EQ(smt.ColumnString(i).find("something"), std::string::npos);
+    }
+  }
+  EXPECT_EQ(2, resultcount);
+
+  // Verify that "encrypted_value" is NOT visible in the file.
+  contents = ReadRawDBContents();
+  EXPECT_NE(0U, contents.length());
+  EXPECT_EQ(contents.find("encrypted_value123XYZ"), std::string::npos);
+  EXPECT_EQ(contents.find("something456ABC"), std::string::npos);
+}
+
+}  // namespace net