[NOT FOR REVIEW] Copy of Max's CL with conflicts fixed

chrome/browser/sync/glue/sync_backend_host.h

-// 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 CHROME_BROWSER_SYNC_GLUE_SYNC_BACKEND_HOST_H_
-#define CHROME_BROWSER_SYNC_GLUE_SYNC_BACKEND_HOST_H_
-
-#include <string>
-
-#include "base/basictypes.h"
-#include "base/callback.h"
-#include "base/compiler_specific.h"
-#include "base/memory/scoped_ptr.h"
-#include "base/threading/thread.h"
-#include "components/sync_driver/backend_data_type_configurer.h"
-#include "sync/internal_api/public/base/model_type.h"
-#include "sync/internal_api/public/configure_reason.h"
-#include "sync/internal_api/public/sessions/sync_session_snapshot.h"
-#include "sync/internal_api/public/shutdown_reason.h"
-#include "sync/internal_api/public/sync_manager.h"
-#include "sync/internal_api/public/sync_manager_factory.h"
-#include "sync/internal_api/public/util/weak_handle.h"
-
-class GURL;
-
-namespace base {
-class MessageLoop;
-}
-
-namespace syncer {
-class CancelationSignal;
-class HttpPostProviderFactory;
-class SyncManagerFactory;
-class UnrecoverableErrorHandler;
-}
-
-namespace sync_driver {
-class ChangeProcessor;
-class SyncFrontend;
-}
-
-namespace browser_sync {
-
-// An API to "host" the top level SyncAPI element.
-//
-// This class handles dispatch of potentially blocking calls to appropriate
-// threads and ensures that the SyncFrontend is only accessed on the UI loop.
-class SyncBackendHost : public sync_driver::BackendDataTypeConfigurer {
- public:
-  typedef syncer::SyncStatus Status;
-  typedef base::Callback<scoped_ptr<syncer::HttpPostProviderFactory>(
-      syncer::CancelationSignal*)> HttpPostProviderFactoryGetter;
-
-  // Stubs used by implementing classes.
-  SyncBackendHost();
-  ~SyncBackendHost() override;
-
-  // Called on the frontend's thread to kick off asynchronous initialization.
-  // Optionally deletes the "Sync Data" folder during init in order to make
-  // sure we're starting fresh.
-  //
-  // |saved_nigori_state| is optional nigori state to restore from a previous
-  // backend instance. May be null.
-  virtual void Initialize(
-      sync_driver::SyncFrontend* frontend,
-      scoped_ptr<base::Thread> sync_thread,
-      const scoped_refptr<base::SingleThreadTaskRunner>& db_thread,
-      const scoped_refptr<base::SingleThreadTaskRunner>& file_thread,
-      const syncer::WeakHandle<syncer::JsEventHandler>& event_handler,
-      const GURL& service_url,
-      const std::string& sync_user_agent,
-      const syncer::SyncCredentials& credentials,
-      bool delete_sync_data_folder,
-      scoped_ptr<syncer::SyncManagerFactory> sync_manager_factory,
-      const syncer::WeakHandle<syncer::UnrecoverableErrorHandler>&
-          unrecoverable_error_handler,
-      const base::Closure& report_unrecoverable_error_function,
-      const HttpPostProviderFactoryGetter& http_post_provider_factory_getter,
-      scoped_ptr<syncer::SyncEncryptionHandler::NigoriState>
-          saved_nigori_state) = 0;
-
-  // Called on the frontend's thread to trigger a refresh.
-  virtual void TriggerRefresh(const syncer::ModelTypeSet& types) = 0;
-
-  // Called on the frontend's thread to update SyncCredentials.
-  virtual void UpdateCredentials(
-      const syncer::SyncCredentials& credentials) = 0;
-
-  // This starts the SyncerThread running a Syncer object to communicate with
-  // sync servers.  Until this is called, no changes will leave or enter this
-  // browser from the cloud / sync servers.
-  // Called on |frontend_loop_|.
-  virtual void StartSyncingWithServer() = 0;
-
-  // Called on |frontend_loop_| to asynchronously set a new passphrase for
-  // encryption. Note that it is an error to call SetEncryptionPassphrase under
-  // the following circumstances:
-  // - An explicit passphrase has already been set
-  // - |is_explicit| is true and we have pending keys.
-  // When |is_explicit| is false, a couple of things could happen:
-  // - If there are pending keys, we try to decrypt them. If decryption works,
-  //   this acts like a call to SetDecryptionPassphrase. If not, the GAIA
-  //   passphrase passed in is cached so we can re-encrypt with it in future.
-  // - If there are no pending keys, data is encrypted with |passphrase| (this
-  //   is a no-op if data was already encrypted with |passphrase|.)
-  virtual void SetEncryptionPassphrase(
-      const std::string& passphrase,
-      bool is_explicit) = 0;
-
-  // Called on |frontend_loop_| to use the provided passphrase to asynchronously
-  // attempt decryption. Returns false immediately if the passphrase could not
-  // be used to decrypt a locally cached copy of encrypted keys; returns true
-  // otherwise. If new encrypted keys arrive during the asynchronous call,
-  // OnPassphraseRequired may be triggered at a later time. It is an error to
-  // call this when there are no pending keys.
-  virtual bool SetDecryptionPassphrase(const std::string& passphrase)
-      WARN_UNUSED_RESULT = 0;
-
-  // Called on |frontend_loop_| to kick off shutdown procedure.  Attempts to cut
-  // short any long-lived or blocking sync thread tasks so that the shutdown on
-  // sync thread task that we're about to post won't have to wait very long.
-  virtual void StopSyncingForShutdown() = 0;
-
-  // Called on |frontend_loop_| to kick off shutdown.
-  // See the implementation and Core::DoShutdown for details.
-  // Must be called *after* StopSyncingForShutdown.
-  // For any reason other than BROWSER_SHUTDOWN, caller should claim sync
-  // thread because:
-  // * during browser shutdown sync thread is not claimed to avoid blocking
-  //   browser shutdown on sync shutdown.
-  // * otherwise sync thread is claimed so that if sync backend is recreated
-  //   later, initialization of new backend is serialized on previous sync
-  //   thread after cleanup of previous backend to avoid old/new backends
-  //   interfere with each other.
-  virtual scoped_ptr<base::Thread> Shutdown(syncer::ShutdownReason reason) = 0;
-
-  // Removes all current registrations from the backend on the
-  // InvalidationService.
-  virtual void UnregisterInvalidationIds() = 0;
-
-  // Changes the set of data types that are currently being synced.
-  // The ready_task will be run when configuration is done with the
-  // set of all types that failed configuration (i.e., if its argument
-  // is non-empty, then an error was encountered).
-  // Returns the set of types that are ready to start without needing any
-  // further sync activity.
-  // BackendDataTypeConfigurer implementation.
-  syncer::ModelTypeSet ConfigureDataTypes(
-      syncer::ConfigureReason reason,
-      const DataTypeConfigStateMap& config_state_map,
-      const base::Callback<void(syncer::ModelTypeSet, syncer::ModelTypeSet)>&
-          ready_task,
-      const base::Callback<void()>& retry_callback) override = 0;
-
-  // Turns on encryption of all present and future sync data.
-  virtual void EnableEncryptEverything() = 0;
-
-  // Called on |frontend_loop_| to obtain a handle to the UserShare needed for
-  // creating transactions.  Should not be called before we signal
-  // initialization is complete with OnBackendInitialized().
-  virtual syncer::UserShare* GetUserShare() const = 0;
-
-  // Called from any thread to obtain current status information in detailed or
-  // summarized form.
-  virtual Status GetDetailedStatus() = 0;
-  virtual syncer::sessions::SyncSessionSnapshot
-      GetLastSessionSnapshot() const = 0;
-
-  // Determines if the underlying sync engine has made any local changes to
-  // items that have not yet been synced with the server.
-  // ONLY CALL THIS IF OnInitializationComplete was called!
-  virtual bool HasUnsyncedItems() const = 0;
-
-  // Whether or not we are syncing encryption keys.
-  virtual bool IsNigoriEnabled() const = 0;
-
-  // Returns the type of passphrase being used to encrypt data. See
-  // sync_encryption_handler.h.
-  virtual syncer::PassphraseType GetPassphraseType() const = 0;
-
-  // If an explicit passphrase is in use, returns the time at which that
-  // passphrase was set (if available).
-  virtual base::Time GetExplicitPassphraseTime() const = 0;
-
-  // True if the cryptographer has any keys available to attempt decryption.
-  // Could mean we've downloaded and loaded Nigori objects, or we bootstrapped
-  // using a token previously received.
-  virtual bool IsCryptographerReady(
-      const syncer::BaseTransaction* trans) const = 0;
-
-  virtual void GetModelSafeRoutingInfo(
-      syncer::ModelSafeRoutingInfo* out) const = 0;
-
-  // Send a message to the sync thread to persist the Directory to disk.
-  virtual void FlushDirectory() const = 0;
-
-  // Requests that the backend forward to the fronent any protocol events in
-  // its buffer and begin forwarding automatically from now on.  Repeated calls
-  // to this function may result in the same events being emitted several
-  // times.
-  virtual void RequestBufferedProtocolEventsAndEnableForwarding() = 0;
-
-  // Disables protocol event forwarding.
-  virtual void DisableProtocolEventForwarding() = 0;
-
-  // Returns a ListValue representing all nodes for the specified types through
-  // |callback| on this thread.
-  virtual void GetAllNodesForTypes(
-      syncer::ModelTypeSet types,
-      base::Callback<void(const std::vector<syncer::ModelType>&,
-                          ScopedVector<base::ListValue>)> type) = 0;
-
-  // Enables the sending of directory type debug counters.  Also, for every
-  // time it is called, it makes an explicit request that updates to an update
-  // for all counters be emitted.
-  virtual void EnableDirectoryTypeDebugInfoForwarding() = 0;
-
-  // Disables the sending of directory type debug counters.
-  virtual void DisableDirectoryTypeDebugInfoForwarding() = 0;
-
-  virtual base::MessageLoop* GetSyncLoopForTesting() = 0;
-
-  // Triggers sync cycle to update |types|.
-  virtual void RefreshTypesForTest(syncer::ModelTypeSet types) = 0;
-
-  // See SyncManager::ClearServerData.
-  virtual void ClearServerData(
-      const syncer::SyncManager::ClearServerDataCallback& callback) = 0;
-
-  DISALLOW_COPY_AND_ASSIGN(SyncBackendHost);
-};
-
-}  // namespace browser_sync
-
-#endif  // CHROME_BROWSER_SYNC_GLUE_SYNC_BACKEND_HOST_H_