[sync] Componentize sync: Part 2: Add SYNC_EXPORTs to files in src/sync/

sync/notifier/invalidation_state_tracker.h

Index: sync/notifier/invalidation_state_tracker.h
diff --git a/sync/notifier/invalidation_state_tracker.h b/sync/notifier/invalidation_state_tracker.h
index 2f268956bad3c480a18b1b03dcad8587f6e25b92..ba769e99dc713eb8dc5e7eef8dfbfd8e5e04705e 100644
--- a/sync/notifier/invalidation_state_tracker.h
+++ b/sync/notifier/invalidation_state_tracker.h
@@ -1,4 +1,4 @@
-// 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.
 //
@@ -19,6 +19,7 @@
 #include "base/callback_forward.h"
 #include "base/memory/ref_counted.h"
 #include "google/cacheinvalidation/include/types.h"
+#include "sync/base/sync_export.h"
 #include "sync/internal_api/public/base/invalidation.h"
 #include "sync/notifier/invalidation_util.h"
 
@@ -28,7 +29,7 @@ class TaskRunner;
 
 namespace syncer {
 
-struct InvalidationState {
+struct SYNC_EXPORT InvalidationState {
   InvalidationState();
   ~InvalidationState();