Add --allow-empty to the commit of the generated dep file.

save_pinned_deps

 #!/bin/bash
 
 # Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # Save the current state of the tree into a pinned deps file that can later
 # be used to reconstruct the same tree.
 
 # Load common constants.  This should be the first executable line.
@@ skipping 81 matching lines @@
 
   rm -f "${TEMPFILE}"
 }
 
 commit_depfile() {
   echo "Commiting pinned DEPS file"
 
   pushd "${DEPPATH}"
 
   git add "${FLAGS_depfile}"
-  git commit -m "Automated buildbot update of pinned DEPS file."
+  git commit -m "Automated buildbot update of pinned DEPS file." --allow-empty
   git reset --hard HEAD
   git clean -f
   git remote update
   git rebase -s ours origin/master
   git push
 
   popd
 }
 
 #
 # Generate a pinned deps file from the current gclient sync and check it into
 # the deps.git repository.
 #
 trap "cleanup" EXIT
 
 if [[ $FLAGS_commit -eq $FLAGS_TRUE ]]; then
   reset_repository
 fi
 
 generate_depfile
 
 if [[ $FLAGS_commit -eq $FLAGS_TRUE ]]; then
   commit_depfile
 fi
 
 trap - EXIT