[Sync] Convert sync to a static library.

components/sync/syncable/model_neutral_mutable_entry.h

Index: components/sync/syncable/model_neutral_mutable_entry.h
diff --git a/components/sync/syncable/model_neutral_mutable_entry.h b/components/sync/syncable/model_neutral_mutable_entry.h
index 005dfeabaed41b5f9b4283ca4386775ea264fdb4..c33aa6f16ad699a8df7878cbd040a5981d2786b9 100644
--- a/components/sync/syncable/model_neutral_mutable_entry.h
+++ b/components/sync/syncable/model_neutral_mutable_entry.h
@@ -12,7 +12,6 @@
 
 #include "base/macros.h"
 #include "components/sync/base/model_type.h"
-#include "components/sync/base/sync_export.h"
 #include "components/sync/syncable/entry.h"
 
 namespace syncer {
@@ -31,7 +30,7 @@ enum CreateNewTypeRoot { CREATE_NEW_TYPE_ROOT };
 // to be communicated to the model (and the model's thread).  It is not possible
 // to change an entry's SPECIFICS or UNIQUE_POSITION fields with this kind of
 // entry.
-class SYNC_EXPORT ModelNeutralMutableEntry : public Entry {
+class ModelNeutralMutableEntry : public Entry {
  public:
   ModelNeutralMutableEntry(BaseWriteTransaction* trans,
                            CreateNewUpdateItem,