Add Mac GN binary to runhooks @ GN revision 235425

TBR=maruel

Review URL: https://codereview.chromium.org/67773005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@235454 0039d316-1c4b-4281-b951-d872f2087c98
Update .DEPS.git

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@235455 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 235455