Forbid remote inspecting with new frontend on old browser.

BUG=336663

Review URL: https://codereview.chromium.org/136093008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@251670 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 251670