[sync] Componentize sync: Part 6: Add more SYNC_EXPORTs to files in src/sync/

sync/syncable/directory_backing_store.h

-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Copyright 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_SYNCABLE_DIRECTORY_BACKING_STORE_H_
 #define SYNC_SYNCABLE_DIRECTORY_BACKING_STORE_H_
 
 #include <string>
 
 #include "base/memory/scoped_ptr.h"
 #include "base/threading/non_thread_safe.h"
 #include "sql/connection.h"
 #include "sql/statement.h"
+#include "sync/base/sync_export.h"
 #include "sync/internal_api/public/base/model_type.h"
 #include "sync/syncable/dir_open_result.h"
 #include "sync/syncable/directory.h"
 #include "sync/syncable/metahandle_set.h"
 
 namespace sync_pb {
 class EntitySpecifics;
 }
 
 namespace syncer {
 namespace syncable {
 
+SYNC_EXPORT_PRIVATE extern const int32 kCurrentDBVersion;
+
 struct ColumnSpec;
 typedef Directory::MetahandlesIndex MetahandlesIndex;
 
 // Interface that provides persistence for a syncable::Directory object. You can
 // load all the persisted data to prime a syncable::Directory on startup by
 // invoking Load.  The only other thing you (or more correctly, a Directory) can
 // do here is save any changes that have occurred since calling Load, which can
 // be done periodically as often as desired.
 //
 // The DirectoryBackingStore will own an sqlite lock on its database for most of
 // its lifetime.  You must not have two DirectoryBackingStore objects accessing
 // the database simultaneously.  Because the lock exists at the database level,
 // not even two separate browser instances would be able to acquire it
 // simultaneously.
 //
 // This class is abstract so that we can extend it in interesting ways for use
 // in tests.  The concrete class used in non-test scenarios is
 // OnDiskDirectoryBackingStore.
-class DirectoryBackingStore : public base::NonThreadSafe {
+class SYNC_EXPORT_PRIVATE DirectoryBackingStore : public base::NonThreadSafe {
  public:
   explicit DirectoryBackingStore(const std::string& dir_name);
   virtual ~DirectoryBackingStore();
 
   // Loads and drops all currently persisted meta entries into |entry_bucket|
   // and loads appropriate persisted kernel info into |info_bucket|.
   //
   // This function can perform some cleanup tasks behind the scenes.  It will
   // clean up unused entries from the database and migrate to the latest
   // database version.  The caller can safely ignore these details.
@@ skipping 116 matching lines @@
   // discarded.
   bool needs_column_refresh_;
 
   DISALLOW_COPY_AND_ASSIGN(DirectoryBackingStore);
 };
 
 }  // namespace syncable
 }  // namespace syncer
 
 #endif  // SYNC_SYNCABLE_DIRECTORY_BACKING_STORE_H_