[Sync] Add support for enabling session sync remotely.

chrome/browser/sync/internal_api/sync_manager.h

 // 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.
 
 #ifndef CHROME_BROWSER_SYNC_INTERNAL_API_SYNC_MANAGER_H_
 #define CHROME_BROWSER_SYNC_INTERNAL_API_SYNC_MANAGER_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 494 matching lines @@
 
   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();
 
+  // Gets the set of encrypted types from the cryptographer
+  // Note: opens a transaction.
   syncable::ModelTypeSet GetEncryptedDataTypes() const;
 
+  // Reads the nigori node to determine if session sync should be enabled.
+  // Note: opens a transaction.
+  bool ShouldEnableSessions() 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(
@@ skipping 10 matching lines @@
 };
 
 bool InitialSyncEndedForTypes(syncable::ModelTypeSet types, UserShare* share);
 
 // Returns the string representation of a PassphraseRequiredReason value.
 std::string PassphraseRequiredReasonToString(PassphraseRequiredReason reason);
 
 } // namespace sync_api
 
 #endif  // CHROME_BROWSER_SYNC_INTERNAL_API_SYNC_MANAGER_H_