Adds the ability for 'copies' in Xcode project files to specify the 'Code Sign on Copy' option.

Relanding change landed in svn:
https://codereview.chromium.org/956203005/

Original author: mattryavec@google.com

BUG=None
R=mark@chromium.org, thakis@chromium.org

Review URL: https://codereview.chromium.org/975443004
3 files changed