Add 's' option to opt string.

Bug: 159159163
Test: build and run
Change-Id: I1217ca75f722bb1bcac019a3b0a3d4debc524925
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2248888
Auto-Submit: Michael Montvelishsky <mont@chromium.org>
Commit-Queue: Kenneth MacKay <kmackay@chromium.org>
Reviewed-by: Kenneth MacKay <kmackay@chromium.org>
Cr-Commit-Position: refs/heads/master@{#779058}

chromecast/media/cma/backend/cplay/cplay.cc

@@ -246,7 +246,7 @@ Parameters ReadArgs(int argc, char* argv[]) {
   Parameters params;
   params.cast_audio_json_path = CastAudioJson::GetFilePath();
   int opt;
-  while ((opt = getopt(argc, argv, "i:o:c:v:d:r:")) != -1) {
+  while ((opt = getopt(argc, argv, "i:o:c:v:d:r:s")) != -1) {
     switch (opt) {
       case 'i':
         params.input_file_path = base::FilePath(optarg);