Added topic flag to git cl split functionality.

Change-Id: Ie3314cfe45e008f1df8b21ff16abda0980a5225e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/4653533
Reviewed-by: Josip Sokcevic <sokcevic@chromium.org>
Commit-Queue: Rachael Newitt <renewitt@google.com>
diff --git a/git_cl.py b/git_cl.py
index 727aa68..d2575f5 100755
--- a/git_cl.py
+++ b/git_cl.py
@@ -5136,6 +5136,9 @@
                     '--max-depth=1 will only split by top-level '
                     'directory. Specifying a value less than 1 means no '
                     'limit on max depth.')
+  parser.add_option('--topic',
+                    default=None,
+                    help='Topic to specify when uploading')
   options, _ = parser.parse_args(args)
 
   if not options.description_file:
@@ -5147,7 +5150,7 @@
   return split_cl.SplitCl(options.description_file, options.comment_file,
                           Changelist, WrappedCMDupload, options.dry_run,
                           options.cq_dry_run, options.enable_auto_submit,
-                          options.max_depth, settings.GetRoot())
+                          options.max_depth, options.topic, settings.GetRoot())
 
 
 @subcommand.usage('DEPRECATED')