make new syncer thread the default.

chrome/browser/sync/engine/syncer_thread2.h

Index: chrome/browser/sync/engine/syncer_thread2.h
diff --git a/chrome/browser/sync/engine/syncer_thread2.h b/chrome/browser/sync/engine/syncer_thread2.h
index 1c698db68365485dee34ef0fbfdf31e681c944ae..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 100644
--- a/chrome/browser/sync/engine/syncer_thread2.h
+++ b/chrome/browser/sync/engine/syncer_thread2.h
@@ -1,344 +0,0 @@
-// Copyright (c) 2011 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.
-//
-// A class to run the syncer on a thread.
-#ifndef CHROME_BROWSER_SYNC_ENGINE_SYNCER_THREAD2_H_
-#define CHROME_BROWSER_SYNC_ENGINE_SYNCER_THREAD2_H_
-#pragma once
-
-#include "base/callback.h"
-#include "base/memory/linked_ptr.h"
-#include "base/memory/scoped_ptr.h"
-#include "base/observer_list.h"
-#include "base/task.h"
-#include "base/threading/thread.h"
-#include "base/time.h"
-#include "base/timer.h"
-#include "chrome/browser/sync/engine/nudge_source.h"
-#include "chrome/browser/sync/engine/polling_constants.h"
-#include "chrome/browser/sync/engine/syncer.h"
-#include "chrome/browser/sync/syncable/model_type_payload_map.h"
-#include "chrome/browser/sync/engine/net/server_connection_manager.h"
-#include "chrome/browser/sync/sessions/sync_session.h"
-#include "chrome/browser/sync/sessions/sync_session_context.h"
-
-namespace browser_sync {
-
-struct ServerConnectionEvent;
-
-namespace s3 {
-
-class SyncerThread : public sessions::SyncSession::Delegate,
-                     public ServerConnectionEventListener {
- public:
-  enum Mode {
-    // In this mode, the thread only performs configuration tasks.  This is
-    // designed to make the case where we want to download updates for a
-    // specific type only, and not continue syncing until we are moved into
-    // normal mode.
-    CONFIGURATION_MODE,
-    // Resumes polling and allows nudges, drops configuration tasks.  Runs
-    // through entire sync cycle.
-    NORMAL_MODE,
-  };
-
-  // Takes ownership of both |context| and |syncer|.
-  SyncerThread(sessions::SyncSessionContext* context, Syncer* syncer);
-  virtual ~SyncerThread();
-
-  typedef Callback0::Type ModeChangeCallback;
-
-  // Change the mode of operation.
-  // We don't use a lock when changing modes, so we won't cause currently
-  // scheduled jobs to adhere to the new mode.  We could protect it, but it
-  // doesn't buy very much as a) a session could already be in progress and it
-  // will continue no matter what, b) the scheduled sessions already contain
-  // all their required state and won't be affected by potential change at
-  // higher levels (i.e. the registrar), and c) we service tasks FIFO, so once
-  // the mode changes all future jobs will be run against the updated mode.
-  // If supplied, |callback| will be invoked when the mode has been
-  // changed to |mode| *from the SyncerThread*, and not from the caller
-  // thread.
-  void Start(Mode mode, ModeChangeCallback* callback);
-
-  // Joins on the thread as soon as possible (currently running session
-  // completes).
-  void Stop();
-
-  // The meat and potatoes.
-  void ScheduleNudge(const base::TimeDelta& delay, NudgeSource source,
-                     const syncable::ModelTypeBitSet& types,
-                     const tracked_objects::Location& nudge_location);
-  void ScheduleNudgeWithPayloads(
-      const base::TimeDelta& delay, NudgeSource source,
-      const syncable::ModelTypePayloadMap& types_with_payloads,
-      const tracked_objects::Location& nudge_location);
-  void ScheduleConfig(const syncable::ModelTypeBitSet& types);
-  void ScheduleClearUserData();
-
-  // Change status of notifications in the SyncSessionContext.
-  void set_notifications_enabled(bool notifications_enabled);
-
-  // DDOS avoidance function.  Calculates how long we should wait before trying
-  // again after a failed sync attempt, where the last delay was |base_delay|.
-  // TODO(tim): Look at URLRequestThrottlerEntryInterface.
-  static base::TimeDelta GetRecommendedDelay(const base::TimeDelta& base_delay);
-
-  // SyncSession::Delegate implementation.
-  virtual void OnSilencedUntil(const base::TimeTicks& silenced_until);
-  virtual bool IsSyncingCurrentlySilenced();
-  virtual void OnReceivedShortPollIntervalUpdate(
-      const base::TimeDelta& new_interval);
-  virtual void OnReceivedLongPollIntervalUpdate(
-      const base::TimeDelta& new_interval);
-  virtual void OnShouldStopSyncingPermanently();
-
-  // ServerConnectionEventListener implementation.
-  // TODO(tim): schedule a nudge when valid connection detected? in 1 minute?
-  virtual void OnServerConnectionEvent(const ServerConnectionEvent2& event);
-
- private:
-  enum JobProcessDecision {
-    // Indicates we should continue with the current job.
-    CONTINUE,
-    // Indicates that we should save it to be processed later.
-    SAVE,
-    // Indicates we should drop this job.
-    DROP,
-  };
-
-  struct SyncSessionJob {
-    // An enum used to describe jobs for scheduling purposes.
-    enum SyncSessionJobPurpose {
-      // Our poll timer schedules POLL jobs periodically based on a server
-      // assigned poll interval.
-      POLL,
-      // A nudge task can come from a variety of components needing to force
-      // a sync.  The source is inferable from |session.source()|.
-      NUDGE,
-      // The user invoked a function in the UI to clear their entire account
-      // and stop syncing (globally).
-      CLEAR_USER_DATA,
-      // Typically used for fetching updates for a subset of the enabled types
-      // during initial sync or reconfiguration.  We don't run all steps of
-      // the sync cycle for these (e.g. CleanupDisabledTypes is skipped).
-      CONFIGURATION,
-    };
-    SyncSessionJob();
-    SyncSessionJob(SyncSessionJobPurpose purpose, base::TimeTicks start,
-        linked_ptr<sessions::SyncSession> session, bool is_canary_job,
-        const tracked_objects::Location& nudge_location);
-    ~SyncSessionJob();
-    SyncSessionJobPurpose purpose;
-    base::TimeTicks scheduled_start;
-    linked_ptr<sessions::SyncSession> session;
-    bool is_canary_job;
-
-    // This is the location the nudge came from. used for debugging purpose.
-    // In case of multiple nudges getting coalesced this stores the first nudge
-    // that came in.
-    tracked_objects::Location nudge_location;
-  };
-  friend class SyncerThread2Test;
-  friend class SyncerThread2WhiteboxTest;
-
-  FRIEND_TEST_ALL_PREFIXES(SyncerThread2WhiteboxTest,
-      DropNudgeWhileExponentialBackOff);
-  FRIEND_TEST_ALL_PREFIXES(SyncerThread2WhiteboxTest, SaveNudge);
-  FRIEND_TEST_ALL_PREFIXES(SyncerThread2WhiteboxTest, ContinueNudge);
-  FRIEND_TEST_ALL_PREFIXES(SyncerThread2WhiteboxTest, DropPoll);
-  FRIEND_TEST_ALL_PREFIXES(SyncerThread2WhiteboxTest, ContinuePoll);
-  FRIEND_TEST_ALL_PREFIXES(SyncerThread2WhiteboxTest, ContinueConfiguration);
-  FRIEND_TEST_ALL_PREFIXES(SyncerThread2WhiteboxTest,
-                           SaveConfigurationWhileThrottled);
-  FRIEND_TEST_ALL_PREFIXES(SyncerThread2WhiteboxTest,
-                           SaveNudgeWhileThrottled);
-  FRIEND_TEST_ALL_PREFIXES(SyncerThread2WhiteboxTest,
-                           ContinueClearUserDataUnderAllCircumstances);
-  FRIEND_TEST_ALL_PREFIXES(SyncerThread2WhiteboxTest,
-                           ContinueCanaryJobConfig);
-  FRIEND_TEST_ALL_PREFIXES(SyncerThread2WhiteboxTest,
-      ContinueNudgeWhileExponentialBackOff);
-
-  // A component used to get time delays associated with exponential backoff.
-  // Encapsulated into a class to facilitate testing.
-  class DelayProvider {
-   public:
-    DelayProvider();
-    virtual base::TimeDelta GetDelay(const base::TimeDelta& last_delay);
-    virtual ~DelayProvider();
-   private:
-    DISALLOW_COPY_AND_ASSIGN(DelayProvider);
-  };
-
-  struct WaitInterval {
-    enum Mode {
-      // A wait interval whose duration has been affected by exponential
-      // backoff.
-      // EXPONENTIAL_BACKOFF intervals are nudge-rate limited to 1 per interval.
-      EXPONENTIAL_BACKOFF,
-      // A server-initiated throttled interval.  We do not allow any syncing
-      // during such an interval.
-      THROTTLED,
-    };
-    WaitInterval();
-    ~WaitInterval();
-
-    Mode mode;
-
-    // This bool is set to true if we have observed a nudge during this
-    // interval and mode == EXPONENTIAL_BACKOFF.
-    bool had_nudge;
-    base::TimeDelta length;
-    base::OneShotTimer<SyncerThread> timer;
-
-    // Configure jobs are saved only when backing off or throttling. So we
-    // expose the pointer here.
-    scoped_ptr<SyncSessionJob> pending_configure_job;
-    WaitInterval(Mode mode, base::TimeDelta length);
-  };
-
-  // Helper to assemble a job and post a delayed task to sync.
-  void ScheduleSyncSessionJob(
-      const base::TimeDelta& delay,
-      SyncSessionJob::SyncSessionJobPurpose purpose,
-      sessions::SyncSession* session,
-      const tracked_objects::Location& nudge_location);
-
-  // Invoke the Syncer to perform a sync.
-  void DoSyncSessionJob(const SyncSessionJob& job);
-
-  // Called after the Syncer has performed the sync represented by |job|, to
-  // reset our state.
-  void FinishSyncSessionJob(const SyncSessionJob& job);
-
-  // Record important state that might be needed in future syncs, such as which
-  // data types may require cleanup.
-  void UpdateCarryoverSessionState(const SyncSessionJob& old_job);
-
-  // Helper to FinishSyncSessionJob to schedule the next sync operation.
-  void ScheduleNextSync(const SyncSessionJob& old_job);
-
-  // Helper to configure polling intervals. Used by Start and ScheduleNextSync.
-  void AdjustPolling(const SyncSessionJob* old_job);
-
-  // Helper to ScheduleNextSync in case of consecutive sync errors.
-  void HandleConsecutiveContinuationError(const SyncSessionJob& old_job);
-
-  // Determines if it is legal to run |job| by checking current
-  // operational mode, backoff or throttling, freshness
-  // (so we don't make redundant syncs), and connection.
-  bool ShouldRunJob(const SyncSessionJob& job);
-
-  // Decide whether we should CONTINUE, SAVE or DROP the job.
-  JobProcessDecision DecideOnJob(const SyncSessionJob& job);
-
-  // Decide on whether to CONTINUE, SAVE or DROP the job when we are in
-  // backoff mode.
-  JobProcessDecision DecideWhileInWaitInterval(const SyncSessionJob& job);
-
-  // Saves the job for future execution. Note: It drops all the poll jobs.
-  void SaveJob(const SyncSessionJob& job);
-
-  // Coalesces the current job with the pending nudge.
-  void InitOrCoalescePendingJob(const SyncSessionJob& job);
-
-  // 'Impl' here refers to real implementation of public functions, running on
-  // |thread_|.
-  void StartImpl(Mode mode, linked_ptr<ModeChangeCallback> callback);
-  void ScheduleNudgeImpl(
-      const base::TimeDelta& delay,
-      sync_pb::GetUpdatesCallerInfo::GetUpdatesSource source,
-      const syncable::ModelTypePayloadMap& types_with_payloads,
-      bool is_canary_job, const tracked_objects::Location& nudge_location);
-  void ScheduleConfigImpl(const ModelSafeRoutingInfo& routing_info,
-      const std::vector<ModelSafeWorker*>& workers,
-      const sync_pb::GetUpdatesCallerInfo::GetUpdatesSource source);
-  void ScheduleClearUserDataImpl();
-
-  // Returns true if the client is currently in exponential backoff.
-  bool IsBackingOff() const;
-
-  // Helper to signal all listeners registered with |session_context_|.
-  void Notify(SyncEngineEvent::EventCause cause);
-
-  // Callback to change backoff state.
-  void DoCanaryJob();
-  void Unthrottle();
-
-  // Executes the pending job. Called whenever an event occurs that may
-  // change conditions permitting a job to run. Like when network connection is
-  // re-established, mode changes etc.
-  void DoPendingJobIfPossible(bool is_canary_job);
-
-  // The pointer is owned by the caller.
-  browser_sync::sessions::SyncSession* CreateSyncSession(
-      const browser_sync::sessions::SyncSourceInfo& info);
-
-  // Creates a session for a poll and performs the sync.
-  void PollTimerCallback();
-
-  // Assign |start| and |end| to appropriate SyncerStep values for the
-  // specified |purpose|.
-  void SetSyncerStepsForPurpose(SyncSessionJob::SyncSessionJobPurpose purpose,
-                                SyncerStep* start,
-                                SyncerStep* end);
-
-  // Initializes the hookup between the ServerConnectionManager and us.
-  void WatchConnectionManager();
-
-  // Used to update |server_connection_ok_|, see below.
-  void CheckServerConnectionManagerStatus(
-      HttpResponse::ServerConnectionCode code);
-
-  // Called once the first time thread_ is started to broadcast an initial
-  // session snapshot containing data like initial_sync_ended.  Important when
-  // the client starts up and does not need to perform an initial sync.
-  void SendInitialSnapshot();
-
-  base::Thread thread_;
-
-  // Modifiable versions of kDefaultLongPollIntervalSeconds which can be
-  // updated by the server.
-  base::TimeDelta syncer_short_poll_interval_seconds_;
-  base::TimeDelta syncer_long_poll_interval_seconds_;
-
-  // Periodic timer for polling.  See AdjustPolling.
-  base::RepeatingTimer<SyncerThread> poll_timer_;
-
-  // The mode of operation. We don't use a lock, see Start(...) comment.
-  Mode mode_;
-
-  // TODO(tim): Bug 26339. This needs to track more than just time I think,
-  // since the nudges could be for different types. Current impl doesn't care.
-  base::TimeTicks last_sync_session_end_time_;
-
-  // Have we observed a valid server connection?
-  bool server_connection_ok_;
-
-  // Tracks in-flight nudges so we can coalesce.
-  scoped_ptr<SyncSessionJob> pending_nudge_;
-
-  // Current wait state.  Null if we're not in backoff and not throttled.
-  scoped_ptr<WaitInterval> wait_interval_;
-
-  scoped_ptr<DelayProvider> delay_provider_;
-
-  // Invoked to run through the sync cycle.
-  scoped_ptr<Syncer> syncer_;
-
-  scoped_ptr<sessions::SyncSessionContext> session_context_;
-
-  DISALLOW_COPY_AND_ASSIGN(SyncerThread);
-};
-
-}  // namespace s3
-
-}  // namespace browser_sync
-
-// The SyncerThread manages its own internal thread and thus outlives it. We
-// don't need refcounting for posting tasks to this internal thread.
-DISABLE_RUNNABLE_METHOD_REFCOUNT(browser_sync::s3::SyncerThread);
-
-#endif  // CHROME_BROWSER_SYNC_ENGINE_SYNCER_THREAD2_H_