Autoroller: Skip commit if there are no DEPS changes.

tools_webrtc/autoroller/roll_deps.py

Index: tools_webrtc/autoroller/roll_deps.py
diff --git a/tools_webrtc/autoroller/roll_deps.py b/tools_webrtc/autoroller/roll_deps.py
index 810cfc4643c5a7dad4dc67d30e6437b98d6428c5..0d87fdc805affba2160cd37aeb47dfbb96830974 100755
--- a/tools_webrtc/autoroller/roll_deps.py
+++ b/tools_webrtc/autoroller/roll_deps.py
@@ -472,9 +472,12 @@ def main():
 
   _CreateRollBranch(opts.dry_run)
   UpdateDepsFile(deps_filename, current_cr_rev, new_cr_rev, changed_deps)
-  _LocalCommit(commit_msg, opts.dry_run)
-  _UploadCL(opts.dry_run, opts.rietveld_email)
-  _SendToCQ(opts.dry_run, opts.skip_cq)
+  if _IsTreeClean():
+    logging.info("No DEPS changes detected, skipping CL creation.")
+  else:
+    _LocalCommit(commit_msg, opts.dry_run)
+    _UploadCL(opts.dry_run, opts.rietveld_email)
+    _SendToCQ(opts.dry_run, opts.skip_cq)
   return 0