sync: Add DeviceInfo protobuf and supporting code

sync/internal_api/sync_manager_impl.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 SYNC_INTERNAL_API_SYNC_MANAGER_H_
 #define SYNC_INTERNAL_API_SYNC_MANAGER_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 226 matching lines @@
   // ExtraPasswordChangeRecordData field of |buffer|. Otherwise sets
   // |buffer|'s specifics field to contain the unencrypted data.
   void SetExtraChangeRecordData(int64 id,
                                 ModelType type,
                                 ChangeReorderBuffer* buffer,
                                 Cryptographer* cryptographer,
                                 const syncable::EntryKernel& original,
                                 bool existed_before,
                                 bool exists_now);
 
-  // Internal callback used by GetSessionName.
-  // TODO(rlarocque): not currently called from anywhere. This should be
-  // hooked up to something once we start preserving device information again.
-  void UpdateSessionNameCallback(const std::string& chrome_version,
-                                 const std::string& session_name);
-
   // Called for every notification. This updates the notification statistics
   // to be displayed in about:sync.
   void UpdateNotificationInfo(
       const ModelTypeInvalidationMap& invalidation_map);
 
   // Checks for server reachabilty and requests a nudge.
   void OnIPAddressChangedImpl();
 
   // Helper function used only by the constructor.
   void BindJsMessageHandler(
@@ skipping 113 matching lines @@
   // changing passphrases, and in general handles sync-specific interactions
   // with the cryptographer.
   scoped_ptr<SyncEncryptionHandlerImpl> sync_encryption_handler_;
 
   DISALLOW_COPY_AND_ASSIGN(SyncManagerImpl);
 };
 
 }  // namespace syncer
 
 #endif  // SYNC_INTERNAL_API_SYNC_MANAGER_H_