DevTools: port forwarding over raw USB won't work

BUG=322543
R=kaznacheev@chromium.org
TBR=kaznacheev

Review URL: https://codereview.chromium.org/83663002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@236803 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 236803