Update mod_test_image_for_staging.sh for session_manager.

Make mod_test_image_for_staging.sh make modifications to
Chrome's command line via the new /etc/chrome_dev.conf file
instead of modifying session_manager_setup.sh.

BUG=chromium:377301
TEST=ran it against a test image
CQ-DEPEND=Iab76d2f4e25463688b3ec7f85513ff27e1da36ff

Change-Id: I514f1e9feacb2e808a2fe1e58329abf41892d08c
Reviewed-on: https://chromium-review.googlesource.com/202380
Tested-by: Daniel Erat <derat@chromium.org>
Reviewed-by: Scott Cunningham <scunningham@chromium.org>
Tested-by: Scott Cunningham <scunningham@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Commit-Queue: Daniel Erat <derat@chromium.org>
1 file changed