[Sync] Convert sync to a static library.

components/sync/core/sync_manager_factory.h

Index: components/sync/core/sync_manager_factory.h
diff --git a/components/sync/core/sync_manager_factory.h b/components/sync/core/sync_manager_factory.h
index 744deabab3655739797adac33ed7f32f45f2f9ce..827d5b6cc7600a48813ead01bffdeb8bee0d2636 100644
--- a/components/sync/core/sync_manager_factory.h
+++ b/components/sync/core/sync_manager_factory.h
@@ -9,14 +9,13 @@
 #include <string>
 
 #include "base/macros.h"
-#include "components/sync/base/sync_export.h"
 
 namespace syncer {
 
 class SyncManager;
 
 // Helper class to allow dependency injection of the SyncManager in tests.
-class SYNC_EXPORT SyncManagerFactory {
+class SyncManagerFactory {
  public:
   SyncManagerFactory();
   virtual ~SyncManagerFactory();