cros proxy: remove unnecessary include file

BUG=none.
TEST=chrome for chromeos compiles successfully.

Review URL: http://codereview.chromium.org/8479048

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@108959 0039d316-1c4b-4281-b951-d872f2087c98
1 file changed