Original patch by rlarocque@chromium.org at http://codereview.chromium.org/7633077/

chrome/browser/sync/engine/syncapi.h

Index: chrome/browser/sync/engine/syncapi.h
diff --git a/chrome/browser/sync/engine/syncapi.h b/chrome/browser/sync/engine/syncapi.h
deleted file mode 100644
index eaf9a56dfca7f9856a75612dda4c24ae6829cb1d..0000000000000000000000000000000000000000
--- a/chrome/browser/sync/engine/syncapi.h
+++ /dev/null
@@ -1,1095 +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.
-
-// This file defines the "sync API", an interface to the syncer
-// backend that exposes (1) the core functionality of maintaining a consistent
-// local snapshot of a hierarchical object set; (2) a means to transactionally
-// access and modify those objects; (3) a means to control client/server
-// synchronization tasks, namely: pushing local object modifications to a
-// server, pulling nonlocal object modifications from a server to this client,
-// and resolving conflicts that may arise between the two; and (4) an
-// abstraction of some external functionality that is to be provided by the
-// host environment.
-//
-// This interface is used as the entry point into the syncer backend
-// when the backend is compiled as a library and embedded in another
-// application.  A goal for this interface layer is to depend on very few
-// external types, so that an application can use the sync backend
-// without introducing a dependency on specific types.  A non-goal is to
-// have binary compatibility across versions or compilers; this allows the
-// interface to use C++ classes.  An application wishing to use the sync API
-// should ideally compile the syncer backend and this API as part of the
-// application's own build, to avoid e.g. mismatches in calling convention,
-// structure padding, or name mangling that could arise if there were a
-// compiler mismatch.
-//
-// The schema of the objects in the sync domain is based on the model, which
-// is essentially a hierarchy of items and folders similar to a filesystem,
-// but with a few important differences.  The sync API contains fields
-// such as URL to easily allow the embedding application to store web
-// browser bookmarks.  Also, the sync API allows duplicate titles in a parent.
-// Consequently, it does not support looking up an object by title
-// and parent, since such a lookup is not uniquely determined.  Lastly,
-// unlike a filesystem model, objects in the Sync API model have a strict
-// ordering within a parent; the position is manipulable by callers, and
-// children of a node can be enumerated in the order of their position.
-
-#ifndef CHROME_BROWSER_SYNC_ENGINE_SYNCAPI_H_
-#define CHROME_BROWSER_SYNC_ENGINE_SYNCAPI_H_
-#pragma once
-
-#include <string>
-#include <vector>
-
-#include "base/basictypes.h"
-#include "base/callback_old.h"
-#include "base/gtest_prod_util.h"
-#include "base/memory/scoped_ptr.h"
-#include "base/tracked.h"
-#include "build/build_config.h"
-#include "chrome/browser/sync/engine/configure_reason.h"
-#include "chrome/browser/sync/protocol/password_specifics.pb.h"
-#include "chrome/browser/sync/syncable/model_type.h"
-#include "chrome/browser/sync/util/cryptographer.h"
-#include "chrome/browser/sync/weak_handle.h"
-#include "chrome/common/net/gaia/google_service_auth_error.h"
-#include "googleurl/src/gurl.h"
-
-class FilePath;
-
-namespace base {
-class DictionaryValue;
-}
-
-namespace browser_sync {
-class JsBackend;
-class JsEventHandler;
-class ModelSafeWorkerRegistrar;
-
-namespace sessions {
-struct SyncSessionSnapshot;
-}
-}
-
-namespace sync_notifier {
-class SyncNotifier;
-}  // namespace sync_notifier
-
-// Forward declarations of internal class types so that sync API objects
-// may have opaque pointers to these types.
-namespace syncable {
-class BaseTransaction;
-class DirectoryManager;
-class Entry;
-class MutableEntry;
-class ReadTransaction;
-class ScopedDirLookup;
-class WriteTransaction;
-}
-
-namespace sync_pb {
-class AppSpecifics;
-class AutofillSpecifics;
-class AutofillProfileSpecifics;
-class BookmarkSpecifics;
-class EntitySpecifics;
-class ExtensionSpecifics;
-class SessionSpecifics;
-class NigoriSpecifics;
-class PasswordSpecifics;
-class PreferenceSpecifics;
-class PasswordSpecifics;
-class PasswordSpecificsData;
-class ThemeSpecifics;
-class TypedUrlSpecifics;
-}
-
-namespace tracked_objects {
-class Location;
-}  // namespace tracked_objects
-
-namespace sync_api {
-
-class BaseTransaction;
-class HttpPostProviderFactory;
-class SyncManager;
-class WriteTransaction;
-
-syncable::ModelTypeSet GetEncryptedTypes(
-    const sync_api::BaseTransaction* trans);
-
-
-// Reasons due to which browser_sync::Cryptographer might require a passphrase.
-enum PassphraseRequiredReason {
-  REASON_PASSPHRASE_NOT_REQUIRED = 0,  // Initial value.
-  REASON_ENCRYPTION = 1,               // The cryptographer requires a
-                                       // passphrase for its first attempt at
-                                       // encryption. Happens only during
-                                       // migration or upgrade.
-  REASON_DECRYPTION = 2,               // The cryptographer requires a
-                                       // passphrase for its first attempt at
-                                       // decryption.
-  REASON_SET_PASSPHRASE_FAILED = 3,    // The cryptographer requires a new
-                                       // passphrase because its attempt at
-                                       // decryption with the cached passphrase
-                                       // was unsuccessful.
-};
-
-// Returns the string representation of a PassphraseRequiredReason value.
-std::string PassphraseRequiredReasonToString(PassphraseRequiredReason reason);
-
-// A UserShare encapsulates the syncable pieces that represent an authenticated
-// user and their data (share).
-// This encompasses all pieces required to build transaction objects on the
-// syncable share.
-struct UserShare {
-  UserShare();
-  ~UserShare();
-
-  // The DirectoryManager itself, which is the parent of Transactions and can
-  // be shared across multiple threads (unlike Directory).
-  scoped_ptr<syncable::DirectoryManager> dir_manager;
-
-  // The username of the sync user.
-  std::string name;
-};
-
-bool InitialSyncEndedForTypes(syncable::ModelTypeSet types, UserShare* share);
-
-// Contains everything needed to talk to and identify a user account.
-struct SyncCredentials {
-  std::string email;
-  std::string sync_token;
-};
-
-// A valid BaseNode will never have an ID of zero.
-static const int64 kInvalidId = 0;
-
-// BaseNode wraps syncable::Entry, and corresponds to a single object's state.
-// This, like syncable::Entry, is intended for use on the stack.  A valid
-// transaction is necessary to create a BaseNode or any of its children.
-// Unlike syncable::Entry, a sync API BaseNode is identified primarily by its
-// int64 metahandle, which we call an ID here.
-class BaseNode {
- public:
-  // All subclasses of BaseNode must provide a way to initialize themselves by
-  // doing an ID lookup.  Returns false on failure.  An invalid or deleted
-  // ID will result in failure.
-  virtual bool InitByIdLookup(int64 id) = 0;
-
-  // All subclasses of BaseNode must also provide a way to initialize themselves
-  // by doing a client tag lookup. Returns false on failure. A deleted node
-  // will return FALSE.
-  virtual bool InitByClientTagLookup(syncable::ModelType model_type,
-      const std::string& tag) = 0;
-
-  // Each object is identified by a 64-bit id (internally, the syncable
-  // metahandle).  These ids are strictly local handles.  They will persist
-  // on this client, but the same object on a different client may have a
-  // different ID value.
-  virtual int64 GetId() const;
-
-  // Returns the modification time of the object (in TimeTicks internal format).
-  int64 GetModificationTime() const;
-
-  // Nodes are hierarchically arranged into a single-rooted tree.
-  // InitByRootLookup on ReadNode allows access to the root. GetParentId is
-  // how you find a node's parent.
-  int64 GetParentId() const;
-
-  // Nodes are either folders or not.  This corresponds to the IS_DIR property
-  // of syncable::Entry.
-  bool GetIsFolder() const;
-
-  // Returns the title of the object.
-  // Uniqueness of the title is not enforced on siblings -- it is not an error
-  // for two children to share a title.
-  std::string GetTitle() const;
-
-  // Returns the model type of this object.  The model type is set at node
-  // creation time and is expected never to change.
-  syncable::ModelType GetModelType() const;
-
-  // Getter specific to the BOOKMARK datatype.  Returns protobuf
-  // data.  Can only be called if GetModelType() == BOOKMARK.
-  const sync_pb::BookmarkSpecifics& GetBookmarkSpecifics() const;
-
-  // Legacy, bookmark-specific getter that wraps GetBookmarkSpecifics() above.
-  // Returns the URL of a bookmark object.
-  // TODO(ncarter): Remove this datatype-specific accessor.
-  GURL GetURL() const;
-
-  // Legacy, bookmark-specific getter that wraps GetBookmarkSpecifics() above.
-  // Fill in a vector with the byte data of this node's favicon.  Assumes
-  // that the node is a bookmark.
-  // Favicons are expected to be PNG images, and though no verification is
-  // done on the syncapi client of this, the server may reject favicon updates
-  // that are invalid for whatever reason.
-  // TODO(ncarter): Remove this datatype-specific accessor.
-  void GetFaviconBytes(std::vector<unsigned char>* output) const;
-
-  // Getter specific to the APPS datatype.  Returns protobuf
-  // data.  Can only be called if GetModelType() == APPS.
-  const sync_pb::AppSpecifics& GetAppSpecifics() const;
-
-  // Getter specific to the AUTOFILL datatype.  Returns protobuf
-  // data.  Can only be called if GetModelType() == AUTOFILL.
-  const sync_pb::AutofillSpecifics& GetAutofillSpecifics() const;
-
-  virtual const sync_pb::AutofillProfileSpecifics&
-      GetAutofillProfileSpecifics() const;
-
-  // Getter specific to the NIGORI datatype.  Returns protobuf
-  // data.  Can only be called if GetModelType() == NIGORI.
-  const sync_pb::NigoriSpecifics& GetNigoriSpecifics() const;
-
-  // Getter specific to the PASSWORD datatype.  Returns protobuf
-  // data.  Can only be called if GetModelType() == PASSWORD.
-  const sync_pb::PasswordSpecificsData& GetPasswordSpecifics() const;
-
-  // Getter specific to the PREFERENCE datatype.  Returns protobuf
-  // data.  Can only be called if GetModelType() == PREFERENCE.
-  const sync_pb::PreferenceSpecifics& GetPreferenceSpecifics() const;
-
-  // Getter specific to the THEME datatype.  Returns protobuf
-  // data.  Can only be called if GetModelType() == THEME.
-  const sync_pb::ThemeSpecifics& GetThemeSpecifics() const;
-
-  // Getter specific to the TYPED_URLS datatype.  Returns protobuf
-  // data.  Can only be called if GetModelType() == TYPED_URLS.
-  const sync_pb::TypedUrlSpecifics& GetTypedUrlSpecifics() const;
-
-  // Getter specific to the EXTENSIONS datatype.  Returns protobuf
-  // data.  Can only be called if GetModelType() == EXTENSIONS.
-  const sync_pb::ExtensionSpecifics& GetExtensionSpecifics() const;
-
-  // Getter specific to the SESSIONS datatype.  Returns protobuf
-  // data.  Can only be called if GetModelType() == SESSIONS.
-  const sync_pb::SessionSpecifics& GetSessionSpecifics() const;
-
-  const sync_pb::EntitySpecifics& GetEntitySpecifics() const;
-
-  // Returns the local external ID associated with the node.
-  int64 GetExternalId() const;
-
-  // Return the ID of the node immediately before this in the sibling order.
-  // For the first node in the ordering, return 0.
-  int64 GetPredecessorId() const;
-
-  // Return the ID of the node immediately after this in the sibling order.
-  // For the last node in the ordering, return 0.
-  virtual int64 GetSuccessorId() const;
-
-  // Return the ID of the first child of this node.  If this node has no
-  // children, return 0.
-  virtual int64 GetFirstChildId() const;
-
-  // These virtual accessors provide access to data members of derived classes.
-  virtual const syncable::Entry* GetEntry() const = 0;
-  virtual const BaseTransaction* GetTransaction() const = 0;
-
-  // Dumps a summary of node info into a DictionaryValue and returns it.
-  // Transfers ownership of the DictionaryValue to the caller.
-  base::DictionaryValue* GetSummaryAsValue() const;
-
-  // Dumps all node details into a DictionaryValue and returns it.
-  // Transfers ownership of the DictionaryValue to the caller.
-  base::DictionaryValue* GetDetailsAsValue() const;
-
- protected:
-  BaseNode();
-  virtual ~BaseNode();
-  // The server has a size limit on client tags, so we generate a fixed length
-  // hash locally. This also ensures that ModelTypes have unique namespaces.
-  static std::string GenerateSyncableHash(syncable::ModelType model_type,
-      const std::string& client_tag);
-
-  // Determines whether part of the entry is encrypted, and if so attempts to
-  // decrypt it. Unless decryption is necessary and fails, this will always
-  // return |true|. If the contents are encrypted, the decrypted data will be
-  // stored in |unencrypted_data_|.
-  // This method is invoked once when the BaseNode is initialized.
-  bool DecryptIfNecessary();
-
-  // Returns the unencrypted specifics associated with |entry|. If |entry| was
-  // not encrypted, it directly returns |entry|'s EntitySpecifics. Otherwise,
-  // returns |unencrypted_data_|.
-  const sync_pb::EntitySpecifics& GetUnencryptedSpecifics(
-      const syncable::Entry* entry) const;
-
-  // Copy |specifics| into |unencrypted_data_|.
-  void SetUnencryptedSpecifics(const sync_pb::EntitySpecifics& specifics);
-
- private:
-  void* operator new(size_t size);  // Node is meant for stack use only.
-
-  // A holder for the unencrypted data stored in an encrypted node.
-  sync_pb::EntitySpecifics unencrypted_data_;
-
-  // Same as |unencrypted_data_|, but for legacy password encryption.
-  scoped_ptr<sync_pb::PasswordSpecificsData> password_data_;
-
-  friend class SyncApiTest;
-  FRIEND_TEST_ALL_PREFIXES(SyncApiTest, GenerateSyncableHash);
-
-  DISALLOW_COPY_AND_ASSIGN(BaseNode);
-};
-
-// WriteNode extends BaseNode to add mutation, and wraps
-// syncable::MutableEntry. A WriteTransaction is needed to create a WriteNode.
-class WriteNode : public BaseNode {
- public:
-  // Create a WriteNode using the given transaction.
-  explicit WriteNode(WriteTransaction* transaction);
-  virtual ~WriteNode();
-
-  // A client must use one (and only one) of the following Init variants to
-  // populate the node.
-
-  // BaseNode implementation.
-  virtual bool InitByIdLookup(int64 id);
-  virtual bool InitByClientTagLookup(syncable::ModelType model_type,
-      const std::string& tag);
-
-  // Create a new node with the specified parent and predecessor.  |model_type|
-  // dictates the type of the item, and controls which EntitySpecifics proto
-  // extension can be used with this item.  Use a NULL |predecessor|
-  // to indicate that this is to be the first child.
-  // |predecessor| must be a child of |new_parent| or NULL. Returns false on
-  // failure.
-  bool InitByCreation(syncable::ModelType model_type,
-                      const BaseNode& parent,
-                      const BaseNode* predecessor);
-
-  // Create nodes using this function if they're unique items that
-  // you want to fetch using client_tag. Note that the behavior of these
-  // items is slightly different than that of normal items.
-  // Most importantly, if it exists locally, this function will
-  // actually undelete it
-  // Client unique tagged nodes must NOT be folders.
-  bool InitUniqueByCreation(syncable::ModelType model_type,
-                            const BaseNode& parent,
-                            const std::string& client_tag);
-
-  // Each server-created permanent node is tagged with a unique string.
-  // Look up the node with the particular tag.  If it does not exist,
-  // return false.
-  bool InitByTagLookup(const std::string& tag);
-
-  // These Set() functions correspond to the Get() functions of BaseNode.
-  void SetIsFolder(bool folder);
-  void SetTitle(const std::wstring& title);
-
-  // External ID is a client-only field, so setting it doesn't cause the item to
-  // be synced again.
-  void SetExternalId(int64 external_id);
-
-  // Remove this node and its children.
-  void Remove();
-
-  // Set a new parent and position.  Position is specified by |predecessor|; if
-  // it is NULL, the node is moved to the first position.  |predecessor| must
-  // be a child of |new_parent| or NULL.  Returns false on failure..
-  bool SetPosition(const BaseNode& new_parent, const BaseNode* predecessor);
-
-  // Set the bookmark specifics (url and favicon).
-  // Should only be called if GetModelType() == BOOKMARK.
-  void SetBookmarkSpecifics(const sync_pb::BookmarkSpecifics& specifics);
-
-  // Legacy, bookmark-specific setters that wrap SetBookmarkSpecifics() above.
-  // Should only be called if GetModelType() == BOOKMARK.
-  // TODO(ncarter): Remove these two datatype-specific accessors.
-  void SetURL(const GURL& url);
-  void SetFaviconBytes(const std::vector<unsigned char>& bytes);
-
-  // Generic set specifics method. Will extract the model type from |specifics|.
-  void SetEntitySpecifics(const sync_pb::EntitySpecifics& specifics);
-
-  // Resets the EntitySpecifics for this node based on the unencrypted data.
-  // Will encrypt if necessary.
-  void ResetFromSpecifics();
-
-  // TODO(sync): Remove the setters below when the corresponding data
-  // types are ported to the new sync service API.
-
-  // Set the app specifics (id, update url, enabled state, etc).
-  // Should only be called if GetModelType() == APPS.
-  void SetAppSpecifics(const sync_pb::AppSpecifics& specifics);
-
-  // Set the autofill specifics (name and value).
-  // Should only be called if GetModelType() == AUTOFILL.
-  void SetAutofillSpecifics(const sync_pb::AutofillSpecifics& specifics);
-
-  void SetAutofillProfileSpecifics(
-      const sync_pb::AutofillProfileSpecifics& specifics);
-
-  // Set the nigori specifics.
-  // Should only be called if GetModelType() == NIGORI.
-  void SetNigoriSpecifics(const sync_pb::NigoriSpecifics& specifics);
-
-  // Set the password specifics.
-  // Should only be called if GetModelType() == PASSWORD.
-  void SetPasswordSpecifics(const sync_pb::PasswordSpecificsData& specifics);
-
-  // Set the theme specifics (name and value).
-  // Should only be called if GetModelType() == THEME.
-  void SetThemeSpecifics(const sync_pb::ThemeSpecifics& specifics);
-
-  // Set the typed_url specifics (url, title, typed_count, etc).
-  // Should only be called if GetModelType() == TYPED_URLS.
-  void SetTypedUrlSpecifics(const sync_pb::TypedUrlSpecifics& specifics);
-
-  // Set the extension specifics (id, update url, enabled state, etc).
-  // Should only be called if GetModelType() == EXTENSIONS.
-  void SetExtensionSpecifics(const sync_pb::ExtensionSpecifics& specifics);
-
-  // Set the session specifics (windows, tabs, navigations etc.).
-  // Should only be called if GetModelType() == SESSIONS.
-  void SetSessionSpecifics(const sync_pb::SessionSpecifics& specifics);
-
-  // Stores |new_specifics| into |entry|, encrypting if necessary.
-  // Returns false if an error encrypting occurred (does not modify |entry|).
-  // Note: gracefully handles new_specifics aliasing with entry->Get(SPECIFICS).
-  static bool UpdateEntryWithEncryption(
-      browser_sync::Cryptographer* cryptographer,
-      const sync_pb::EntitySpecifics& new_specifics,
-      syncable::MutableEntry* entry);
-
-  // Implementation of BaseNode's abstract virtual accessors.
-  virtual const syncable::Entry* GetEntry() const;
-
-  virtual const BaseTransaction* GetTransaction() const;
-
- private:
-  void* operator new(size_t size);  // Node is meant for stack use only.
-
-  // Helper to set model type. This will clear any specifics data.
-  void PutModelType(syncable::ModelType model_type);
-
-  // Helper to set the previous node.
-  void PutPredecessor(const BaseNode* predecessor);
-
-  // Sets IS_UNSYNCED and SYNCING to ensure this entry is considered in an
-  // upcoming commit pass.
-  void MarkForSyncing();
-
-  // The underlying syncable object which this class wraps.
-  syncable::MutableEntry* entry_;
-
-  // The sync API transaction that is the parent of this node.
-  WriteTransaction* transaction_;
-
-  DISALLOW_COPY_AND_ASSIGN(WriteNode);
-};
-
-// ReadNode wraps a syncable::Entry to provide the functionality of a
-// read-only BaseNode.
-class ReadNode : public BaseNode {
- public:
-  // Create an unpopulated ReadNode on the given transaction.  Call some flavor
-  // of Init to populate the ReadNode with a database entry.
-  explicit ReadNode(const BaseTransaction* transaction);
-  virtual ~ReadNode();
-
-  // A client must use one (and only one) of the following Init variants to
-  // populate the node.
-
-  // BaseNode implementation.
-  virtual bool InitByIdLookup(int64 id);
-  virtual bool InitByClientTagLookup(syncable::ModelType model_type,
-      const std::string& tag);
-
-  // There is always a root node, so this can't fail.  The root node is
-  // never mutable, so root lookup is only possible on a ReadNode.
-  void InitByRootLookup();
-
-  // Each server-created permanent node is tagged with a unique string.
-  // Look up the node with the particular tag.  If it does not exist,
-  // return false.
-  bool InitByTagLookup(const std::string& tag);
-
-  // Implementation of BaseNode's abstract virtual accessors.
-  virtual const syncable::Entry* GetEntry() const;
-  virtual const BaseTransaction* GetTransaction() const;
-
- protected:
-  ReadNode();
-
- private:
-  void* operator new(size_t size);  // Node is meant for stack use only.
-
-  // The underlying syncable object which this class wraps.
-  syncable::Entry* entry_;
-
-  // The sync API transaction that is the parent of this node.
-  const BaseTransaction* transaction_;
-
-  DISALLOW_COPY_AND_ASSIGN(ReadNode);
-};
-
-// Sync API's BaseTransaction, ReadTransaction, and WriteTransaction allow for
-// batching of several read and/or write operations.  The read and write
-// operations are performed by creating ReadNode and WriteNode instances using
-// the transaction. These transaction classes wrap identically named classes in
-// syncable, and are used in a similar way. Unlike syncable::BaseTransaction,
-// whose construction requires an explicit syncable::ScopedDirLookup, a sync
-// API BaseTransaction creates its own ScopedDirLookup implicitly.
-class BaseTransaction {
- public:
-  // Provide access to the underlying syncable.h objects from BaseNode.
-  virtual syncable::BaseTransaction* GetWrappedTrans() const = 0;
-  const syncable::ScopedDirLookup& GetLookup() const { return *lookup_; }
-  browser_sync::Cryptographer* GetCryptographer() const {
-    return cryptographer_;
-  }
-
- protected:
-  // The ScopedDirLookup is created in the constructor and destroyed
-  // in the destructor.  Creation of the ScopedDirLookup is not expected
-  // to fail.
-  explicit BaseTransaction(UserShare* share);
-  virtual ~BaseTransaction();
-
-  BaseTransaction() { lookup_= NULL; }
-
- private:
-  // A syncable ScopedDirLookup, which is the parent of syncable transactions.
-  syncable::ScopedDirLookup* lookup_;
-
-  browser_sync::Cryptographer* cryptographer_;
-
-  DISALLOW_COPY_AND_ASSIGN(BaseTransaction);
-};
-
-// TODO(akalin): Make ReadTransaction/WriteTransaction take a Location
-// parameter.
-
-// Sync API's ReadTransaction is a read-only BaseTransaction.  It wraps
-// a syncable::ReadTransaction.
-class ReadTransaction : public BaseTransaction {
- public:
-  // Start a new read-only transaction on the specified repository.
-  ReadTransaction(const tracked_objects::Location& from_here,
-                  UserShare* share);
-
-  // Resume the middle of a transaction. Will not close transaction.
-  ReadTransaction(UserShare* share, syncable::BaseTransaction* trans);
-
-  virtual ~ReadTransaction();
-
-  // BaseTransaction override.
-  virtual syncable::BaseTransaction* GetWrappedTrans() const;
- private:
-  void* operator new(size_t size);  // Transaction is meant for stack use only.
-
-  // The underlying syncable object which this class wraps.
-  syncable::BaseTransaction* transaction_;
-  bool close_transaction_;
-
-  DISALLOW_COPY_AND_ASSIGN(ReadTransaction);
-};
-
-// Sync API's WriteTransaction is a read/write BaseTransaction.  It wraps
-// a syncable::WriteTransaction.
-//
-// NOTE: Only a single model type can be mutated for a given
-// WriteTransaction.
-class WriteTransaction : public BaseTransaction {
- public:
-  // Start a new read/write transaction.
-  WriteTransaction(const tracked_objects::Location& from_here,
-                   UserShare* share);
-  virtual ~WriteTransaction();
-
-  // Provide access to the syncable.h transaction from the API WriteNode.
-  virtual syncable::BaseTransaction* GetWrappedTrans() const;
-  syncable::WriteTransaction* GetWrappedWriteTrans() { return transaction_; }
-
- protected:
-  WriteTransaction() {}
-
-  void SetTransaction(syncable::WriteTransaction* trans) {
-      transaction_ = trans;
-  }
-
- private:
-  void* operator new(size_t size);  // Transaction is meant for stack use only.
-
-  // The underlying syncable object which this class wraps.
-  syncable::WriteTransaction* transaction_;
-
-  DISALLOW_COPY_AND_ASSIGN(WriteTransaction);
-};
-
-// SyncManager encapsulates syncable::DirectoryManager and serves as the parent
-// of all other objects in the sync API.  SyncManager is thread-safe.  If
-// multiple threads interact with the same local sync repository (i.e. the
-// same sqlite database), they should share a single SyncManager instance.  The
-// caller should typically create one SyncManager for the lifetime of a user
-// session.
-class SyncManager {
- public:
-  // SyncInternal contains the implementation of SyncManager, while abstracting
-  // internal types from clients of the interface.
-  class SyncInternal;
-
-  // TODO(zea): One day get passwords playing nicely with the rest of encryption
-  // and get rid of this.
-  class ExtraPasswordChangeRecordData {
-   public:
-    ExtraPasswordChangeRecordData();
-    explicit ExtraPasswordChangeRecordData(
-        const sync_pb::PasswordSpecificsData& data);
-    virtual ~ExtraPasswordChangeRecordData();
-
-    // Transfers ownership of the DictionaryValue to the caller.
-    virtual base::DictionaryValue* ToValue() const;
-
-    const sync_pb::PasswordSpecificsData& unencrypted() const;
-   private:
-    sync_pb::PasswordSpecificsData unencrypted_;
-  };
-
-  // ChangeRecord indicates a single item that changed as a result of a sync
-  // operation.  This gives the sync id of the node that changed, and the type
-  // of change.  To get the actual property values after an ADD or UPDATE, the
-  // client should get the node with InitByIdLookup(), using the provided id.
-  struct ChangeRecord {
-    enum Action {
-      ACTION_ADD,
-      ACTION_DELETE,
-      ACTION_UPDATE,
-    };
-    ChangeRecord();
-    ~ChangeRecord();
-
-    // Transfers ownership of the DictionaryValue to the caller.
-    base::DictionaryValue* ToValue(const BaseTransaction* trans) const;
-
-    int64 id;
-    Action action;
-    sync_pb::EntitySpecifics specifics;
-    linked_ptr<ExtraPasswordChangeRecordData> extra;
-  };
-
-  // Status encapsulates detailed state about the internals of the SyncManager.
-  struct Status {
-    // Summary is a distilled set of important information that the end-user may
-    // wish to be informed about (through UI, for example). Note that if a
-    // summary state requires user interaction (such as auth failures), more
-    // detailed information may be contained in additional status fields.
-    enum Summary {
-      // The internal instance is in an unrecognizable state. This should not
-      // happen.
-      INVALID = 0,
-      // Can't connect to server, but there are no pending changes in
-      // our local cache.
-      OFFLINE,
-      // Can't connect to server, and there are pending changes in our
-      // local cache.
-      OFFLINE_UNSYNCED,
-      // Connected and syncing.
-      SYNCING,
-      // Connected, no pending changes.
-      READY,
-      // Internal sync error.
-      CONFLICT,
-      // Can't connect to server, and we haven't completed the initial
-      // sync yet.  So there's nothing we can do but wait for the server.
-      OFFLINE_UNUSABLE,
-
-      SUMMARY_STATUS_COUNT,
-    };
-
-    Status();
-    ~Status();
-
-    Summary summary;
-    bool authenticated;      // Successfully authenticated via GAIA.
-    bool server_up;          // True if we have received at least one good
-                             // reply from the server.
-    bool server_reachable;   // True if we received any reply from the server.
-    bool server_broken;      // True of the syncer is stopped because of server
-                             // issues.
-    bool notifications_enabled;  // True only if subscribed for notifications.
-
-    // Notifications counters updated by the actions in synapi.
-    int notifications_received;
-    int notifiable_commits;
-
-    // The max number of consecutive errors from any component.
-    int max_consecutive_errors;
-
-    int unsynced_count;
-
-    int conflicting_count;
-    bool syncing;
-    // True after a client has done a first sync.
-    bool initial_sync_ended;
-    // True if any syncer is stuck.
-    bool syncer_stuck;
-
-    // Total updates available.  If zero, nothing left to download.
-    int64 updates_available;
-    // Total updates received by the syncer since browser start.
-    int updates_received;
-
-    // Of updates_received, how many were tombstones.
-    int tombstone_updates_received;
-    bool disk_full;
-
-    // Total number of overwrites due to conflict resolver since browser start.
-    int num_local_overwrites_total;
-    int num_server_overwrites_total;
-
-    // Count of empty and non empty getupdates;
-    int nonempty_get_updates;
-    int empty_get_updates;
-
-    // Count of useless and useful syncs we perform.
-    int useless_sync_cycles;
-    int useful_sync_cycles;
-
-    // Encryption related.
-    syncable::ModelTypeSet encrypted_types;
-    bool cryptographer_ready;
-    bool crypto_has_pending_keys;
-  };
-
-  // An interface the embedding application implements to receive notifications
-  // from the SyncManager.  Register an observer via SyncManager::AddObserver.
-  // This observer is an event driven model as the events may be raised from
-  // different internal threads, and simply providing an "OnStatusChanged" type
-  // notification complicates things such as trying to determine "what changed",
-  // if different members of the Status object are modified from different
-  // threads.  This way, the event is explicit, and it is safe for the Observer
-  // to dispatch to a native thread or synchronize accordingly.
-  class Observer {
-   public:
-    // Notify the observer that changes have been applied to the sync model.
-    //
-    // This will be invoked on the same thread as on which ApplyChanges was
-    // called. |changes| is an array of size |change_count|, and contains the
-    // ID of each individual item that was changed. |changes| exists only for
-    // the duration of the call. If items of multiple data types change at
-    // the same time, this method is invoked once per data type and |changes|
-    // is restricted to items of the ModelType indicated by |model_type|.
-    // Because the observer is passed a |trans|, the observer can assume a
-    // read lock on the sync model that will be released after the function
-    // returns.
-    //
-    // The SyncManager constructs |changes| in the following guaranteed order:
-    //
-    // 1. Deletions, from leaves up to parents.
-    // 2. Updates to existing items with synced parents & predecessors.
-    // 3. New items with synced parents & predecessors.
-    // 4. Items with parents & predecessors in |changes|.
-    // 5. Repeat #4 until all items are in |changes|.
-    //
-    // Thus, an implementation of OnChangesApplied should be able to
-    // process the change records in the order without having to worry about
-    // forward dependencies.  But since deletions come before reparent
-    // operations, a delete may temporarily orphan a node that is
-    // updated later in the list.
-    virtual void OnChangesApplied(syncable::ModelType model_type,
-                                  const BaseTransaction* trans,
-                                  const ChangeRecord* changes,
-                                  int change_count) = 0;
-
-    // OnChangesComplete gets called when the TransactionComplete event is
-    // posted (after OnChangesApplied finishes), after the transaction lock
-    // and the change channel mutex are released.
-    //
-    // The purpose of this function is to support processors that require
-    // split-transactions changes. For example, if a model processor wants to
-    // perform blocking I/O due to a change, it should calculate the changes
-    // while holding the transaction lock (from within OnChangesApplied), buffer
-    // those changes, let the transaction fall out of scope, and then commit
-    // those changes from within OnChangesComplete (postponing the blocking
-    // I/O to when it no longer holds any lock).
-    virtual void OnChangesComplete(syncable::ModelType model_type) = 0;
-
-    // A round-trip sync-cycle took place and the syncer has resolved any
-    // conflicts that may have arisen.
-    virtual void OnSyncCycleCompleted(
-        const browser_sync::sessions::SyncSessionSnapshot* snapshot) = 0;
-
-    // Called when user interaction may be required due to an auth problem.
-    virtual void OnAuthError(const GoogleServiceAuthError& auth_error) = 0;
-
-    // Called when a new auth token is provided by the sync server.
-    virtual void OnUpdatedToken(const std::string& token) = 0;
-
-    // Called when user interaction is required to obtain a valid passphrase.
-    // - If the passphrase is required for encryption, |reason| will be
-    //   REASON_ENCRYPTION.
-    // - If the passphrase is required for the decryption of data that has
-    //   already been encrypted, |reason| will be REASON_DECRYPTION.
-    // - If the passphrase is required because decryption failed, and a new
-    //   passphrase is required, |reason| will be REASON_SET_PASSPHRASE_FAILED.
-    virtual void OnPassphraseRequired(PassphraseRequiredReason reason) = 0;
-
-    // Called when the passphrase provided by the user has been accepted and is
-    // now used to encrypt sync data.  |bootstrap_token| is an opaque base64
-    // encoded representation of the key generated by the accepted passphrase,
-    // and is provided to the observer for persistence purposes and use in a
-    // future initialization of sync (e.g. after restart).
-    virtual void OnPassphraseAccepted(const std::string& bootstrap_token) = 0;
-
-    // Called when initialization is complete to the point that SyncManager can
-    // process changes. This does not necessarily mean authentication succeeded
-    // or that the SyncManager is online.
-    // IMPORTANT: Creating any type of transaction before receiving this
-    // notification is illegal!
-    // WARNING: Calling methods on the SyncManager before receiving this
-    // message, unless otherwise specified, produces undefined behavior.
-    //
-    // |js_backend| is what about:sync interacts with.  It can emit
-    // the following events:
-
-    /**
-     * @param {{ enabled: boolean }} details A dictionary containing:
-     *     - enabled: whether or not notifications are enabled.
-     */
-    // function onNotificationStateChange(details);
-
-    /**
-     * @param {{ changedTypes: Array.<string> }} details A dictionary
-     *     containing:
-     *     - changedTypes: a list of types (as strings) for which there
-             are new updates.
-     */
-    // function onIncomingNotification(details);
-
-    // Also, it responds to the following messages (all other messages
-    // are ignored):
-
-    /**
-     * Gets the current notification state.
-     *
-     * @param {function(boolean)} callback Called with whether or not
-     *     notifications are enabled.
-     */
-    // function getNotificationState(callback);
-
-    /**
-     * Gets details about the root node.
-     *
-     * @param {function(!Object)} callback Called with details about the
-     *     root node.
-     */
-    // TODO(akalin): Change this to getRootNodeId or eliminate it
-    // entirely.
-    // function getRootNodeDetails(callback);
-
-    /**
-     * Gets summary information for a list of ids.
-     *
-     * @param {Array.<string>} idList List of 64-bit ids in decimal
-     *     string form.
-     * @param {Array.<{id: string, title: string, isFolder: boolean}>}
-     * callback Called with summaries for the nodes in idList that
-     *     exist.
-     */
-    // function getNodeSummariesById(idList, callback);
-
-    /**
-     * Gets detailed information for a list of ids.
-     *
-     * @param {Array.<string>} idList List of 64-bit ids in decimal
-     *     string form.
-     * @param {Array.<!Object>} callback Called with detailed
-     *     information for the nodes in idList that exist.
-     */
-    // function getNodeDetailsById(idList, callback);
-
-    /**
-     * Gets child ids for a given id.
-     *
-     * @param {string} id 64-bit id in decimal string form of the parent
-     *     node.
-     * @param {Array.<string>} callback Called with the (possibly empty)
-     *     list of child ids.
-     */
-    // function getChildNodeIds(id);
-
-    virtual void OnInitializationComplete(
-        const browser_sync::WeakHandle<browser_sync::JsBackend>&
-            js_backend) = 0;
-
-    // We are no longer permitted to communicate with the server. Sync should
-    // be disabled and state cleaned up at once.  This can happen for a number
-    // of reasons, e.g. swapping from a test instance to production, or a
-    // global stop syncing operation has wiped the store.
-    virtual void OnStopSyncingPermanently() = 0;
-
-    // After a request to clear server data, these callbacks are invoked to
-    // indicate success or failure.
-    virtual void OnClearServerDataSucceeded() = 0;
-    virtual void OnClearServerDataFailed() = 0;
-
-    // Called after we finish encrypting all appropriate datatypes.
-    virtual void OnEncryptionComplete(
-        const syncable::ModelTypeSet& encrypted_types) = 0;
-
-   protected:
-    virtual ~Observer();
-  };
-
-  typedef Callback0::Type ModeChangeCallback;
-
-  // Create an uninitialized SyncManager.  Callers must Init() before using.
-  explicit SyncManager(const std::string& name);
-  virtual ~SyncManager();
-
-  // Initialize the sync manager.  |database_location| specifies the path of
-  // the directory in which to locate a sqlite repository storing the syncer
-  // backend state. Initialization will open the database, or create it if it
-  // does not already exist. Returns false on failure.
-  // |event_handler| is the JsEventHandler used to propagate events to
-  // chrome://sync-internals.  |event_handler| may be uninitialized.
-  // |sync_server_and_path| and |sync_server_port| represent the Chrome sync
-  // server to use, and |use_ssl| specifies whether to communicate securely;
-  // the default is false.
-  // |post_factory| will be owned internally and used to create
-  // instances of an HttpPostProvider.
-  // |model_safe_worker| ownership is given to the SyncManager.
-  // |user_agent| is a 7-bit ASCII string suitable for use as the User-Agent
-  // HTTP header. Used internally when collecting stats to classify clients.
-  // |sync_notifier| is owned and used to listen for notifications.
-  bool Init(const FilePath& database_location,
-            const browser_sync::WeakHandle<browser_sync::JsEventHandler>&
-                event_handler,
-            const std::string& sync_server_and_path,
-            int sync_server_port,
-            bool use_ssl,
-            HttpPostProviderFactory* post_factory,
-            browser_sync::ModelSafeWorkerRegistrar* registrar,
-            const std::string& user_agent,
-            const SyncCredentials& credentials,
-            sync_notifier::SyncNotifier* sync_notifier,
-            const std::string& restored_key_for_bootstrapping,
-            bool setup_for_test_mode);
-
-  // Returns the username last used for a successful authentication.
-  // Returns empty if there is no such username.
-  const std::string& GetAuthenticatedUsername();
-
-  // Check if the database has been populated with a full "initial" download of
-  // sync items for each data type currently present in the routing info.
-  // Prerequisite for calling this is that OnInitializationComplete has been
-  // called.
-  bool InitialSyncEndedForAllEnabledTypes();
-
-  // Update tokens that we're using in Sync. Email must stay the same.
-  void UpdateCredentials(const SyncCredentials& credentials);
-
-  // Called when the user disables or enables a sync type.
-  void UpdateEnabledTypes();
-
-  // Put the syncer in normal mode ready to perform nudges and polls.
-  void StartSyncingNormally();
-
-  // Attempt to set the passphrase. If the passphrase is valid,
-  // OnPassphraseAccepted will be fired to notify the ProfileSyncService and the
-  // syncer will be nudged so that any update that was waiting for this
-  // passphrase gets applied as soon as possible.
-  // If the passphrase in invalid, OnPassphraseRequired will be fired.
-  // Calling this metdod again is the appropriate course of action to "retry"
-  // with a new passphrase.
-  // |is_explicit| is true if the call is in response to the user explicitly
-  // setting a passphrase as opposed to implicitly (from the users' perspective)
-  // using their Google Account password.  An implicit SetPassphrase will *not*
-  // *not* override an explicit passphrase set previously.
-  void SetPassphrase(const std::string& passphrase, bool is_explicit);
-
-  // Set the datatypes we want to encrypt and encrypt any nodes as necessary.
-  // Note: |encrypted_types| will be unioned with the current set of encrypted
-  // types, as we do not currently support decrypting datatypes.
-  void EncryptDataTypes(const syncable::ModelTypeSet& encrypted_types);
-
-  // Puts the SyncScheduler into a mode where no normal nudge or poll traffic
-  // will occur, but calls to RequestConfig will be supported.  If |callback|
-  // is provided, it will be invoked (from the internal SyncScheduler) when
-  // the thread has changed to configuration mode.
-  void StartConfigurationMode(ModeChangeCallback* callback);
-
-  // Switches the mode of operation to CONFIGURATION_MODE and
-  // schedules a config task to fetch updates for |types|.
-  void RequestConfig(const syncable::ModelTypeBitSet& types,
-     sync_api::ConfigureReason reason);
-
-  void RequestCleanupDisabledTypes();
-
-  // Request a clearing of all data on the server
-  void RequestClearServerData();
-
-  // Adds a listener to be notified of sync events.
-  // NOTE: It is OK (in fact, it's probably a good idea) to call this before
-  // having received OnInitializationCompleted.
-  void AddObserver(Observer* observer);
-
-  // Remove the given observer.  Make sure to call this if the
-  // Observer is being destroyed so the SyncManager doesn't
-  // potentially dereference garbage.
-  void RemoveObserver(Observer* observer);
-
-  // Status-related getters. Typically GetStatusSummary will suffice, but
-  // GetDetailedSyncStatus can be useful for gathering debug-level details of
-  // the internals of the sync engine.
-  Status::Summary GetStatusSummary() const;
-  Status GetDetailedStatus() const;
-
-  // Whether or not the Nigori node is encrypted using an explicit passphrase.
-  bool IsUsingExplicitPassphrase();
-
-  // Get the internal implementation for use by BaseTransaction, etc.
-  SyncInternal* GetImpl() const;
-
-  // Call periodically from a database-safe thread to persist recent changes
-  // to the syncapi model.
-  void SaveChanges();
-
-  void RequestEarlyExit();
-
-  // Issue a final SaveChanges, close sqlite handles, and stop running threads.
-  // Must be called from the same thread that called Init().
-  void Shutdown();
-
-  UserShare* GetUserShare() const;
-
-  // Inform the cryptographer of the most recent passphrase and set of encrypted
-  // types (from nigori node), then ensure all data that needs encryption is
-  // encrypted with the appropriate passphrase.
-  // Note: opens a transaction and can trigger ON_PASSPHRASE_REQUIRED, so must
-  // only be called after syncapi has been initialized.
-  void RefreshEncryption();
-
-  syncable::ModelTypeSet GetEncryptedDataTypes() const;
-
-  // Uses a read-only transaction to determine if the directory being synced has
-  // any remaining unsynced items.
-  bool HasUnsyncedItems() const;
-
-  // Logs the list of unsynced meta handles.
-  void LogUnsyncedItems(int level) const;
-
-  // Functions used for testing.
-
-  void TriggerOnNotificationStateChangeForTest(
-      bool notifications_enabled);
-
-  void TriggerOnIncomingNotificationForTest(
-      const syncable::ModelTypeBitSet& model_types);
-
- private:
-  // An opaque pointer to the nested private class.
-  SyncInternal* data_;
-
-  DISALLOW_COPY_AND_ASSIGN(SyncManager);
-};
-
-}  // namespace sync_api
-
-#endif  // CHROME_BROWSER_SYNC_ENGINE_SYNCAPI_H_