gclient sync -D doesn't do much without --force now.

> WARNING: 'src/third_party/devtools-node-modules' is no longer part of this client.
> Despite running 'gclient sync -D' no action was taken as there are modifications.
> It is recommended you revert all changes or run 'gclient sync -D --force' next time.

Change-Id: I00ecf1e0f222589fcc475a27955d19fc53e2b562