Update reference file of "register-pepper-plugins" format.

The format is now stated in pepper_plugin_list.cc.

BUG=none
TEST=none
R=jam@chromium.org

Review URL: https://codereview.chromium.org/27442002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@228941 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 228941