Fix CRLF line endings in id_mapping_helper* files.

TBR=lipalani@chromium.org

Review URL: https://codereview.chromium.org/65203005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@235257 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 235257