change newly added OVERRIDE to override in sync/

sync/internal_api/attachments/attachment_store_handle_unittest.cc

Index: sync/internal_api/attachments/attachment_store_handle_unittest.cc
diff --git a/sync/internal_api/attachments/attachment_store_handle_unittest.cc b/sync/internal_api/attachments/attachment_store_handle_unittest.cc
index e99f6e131ae1818233cff10e4baf6bf5328fbb26..a282c607977ab5719acf04bba0ab6175f255056f 100644
--- a/sync/internal_api/attachments/attachment_store_handle_unittest.cc
+++ b/sync/internal_api/attachments/attachment_store_handle_unittest.cc
@@ -35,17 +35,17 @@ class MockAttachmentStore : public AttachmentStoreBase {
   }
 
   virtual void Read(const AttachmentIdList& ids,
-                    const ReadCallback& callback) OVERRIDE {
+                    const ReadCallback& callback) override {
     read_called_.Run();
   }
 
   virtual void Write(const AttachmentList& attachments,
-                     const WriteCallback& callback) OVERRIDE {
+                     const WriteCallback& callback) override {
     write_called_.Run();
   }
 
   virtual void Drop(const AttachmentIdList& ids,
-                    const DropCallback& callback) OVERRIDE {
+                    const DropCallback& callback) override {
     drop_called_.Run();
   }