Call SetPassphrase() to re-encrypt the user's data after re-auth.

chrome/browser/sync/sync_setup_flow.cc

Index: chrome/browser/sync/sync_setup_flow.cc
diff --git a/chrome/browser/sync/sync_setup_flow.cc b/chrome/browser/sync/sync_setup_flow.cc
index a08bab1cd07ebe150914d5311b827970d0cb88bb..2cd8aa203c9fd7c2564e74e5aa03a9561add6db7 100644
--- a/chrome/browser/sync/sync_setup_flow.cc
+++ b/chrome/browser/sync/sync_setup_flow.cc
@@ -438,6 +438,15 @@ void SyncSetupFlow::ActivateState(SyncSetupWizard::State state) {
     }
     case SyncSetupWizard::GAIA_SUCCESS:
       if (end_state_ == SyncSetupWizard::GAIA_SUCCESS) {
+        // The user has just re-authed - set the passphrase so we can re-encrypt
+        // if necessary. If we are currently encrypting with an explicit
+        // passphrase, this does nothing.
+        // TODO(atwilson): Move all the code dealing with the implicit GAIA
+        // passphrase back into ProfileSyncService in a
+        // NOTIFICATION_GOOGLE_SIGNIN_SUCCESSFUL listener once we get rid of
+        // SyncSetupFlow.
+        if (!cached_passphrase_.empty())
+          service_->SetPassphrase(cached_passphrase_, false);
         flow_handler_->ShowGaiaSuccessAndClose();
         break;
       }