[Sync] Add sync_export.h (Step 1 for componentizing sync)

sync/internal_api/public/engine/sync_status.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_PUBLIC_ENGINE_STATUS_SUMMARY_H_
 #define SYNC_INTERNAL_API_PUBLIC_ENGINE_STATUS_SUMMARY_H_
 
 #include <string>
 
+#include "sync/base/sync_export.h"
 #include "sync/internal_api/public/base/model_type.h"
 #include "sync/protocol/sync_protocol_error.h"
 
 namespace syncer {
 
 // Status encapsulates detailed state about the internals of the SyncManager.
 //
 // This struct is closely tied to the AllStatus object which uses instances of
 // it to track and report on the sync engine's internal state, and the functions
 // in sync_ui_util.cc which convert the contents of this struct into a
 // DictionaryValue used to populate the about:sync summary tab.
-struct SyncStatus {
+struct SYNC_EXPORT SyncStatus {
   SyncStatus();
   ~SyncStatus();
 
   // TODO(akalin): Replace this with a NotificationsDisabledReason
   // variable.
   bool notifications_enabled;  // True only if subscribed for notifications.
 
   // Notifications counters updated by the actions in synapi.
   int notifications_received;
 
@@ skipping 55 matching lines @@
   // Per-datatype throttled status.
   syncer::ModelTypeSet throttled_types;
 
   // The unique identifer for this client.
   std::string unique_id;
 };
 
 }  // namespace syncer
 
 #endif  // SYNC_INTERNAL_API_PUBLIC_ENGINE_STATUS_SUMMARY_H_