WebSocketChannel should ensure the scheme is "ws" or "wss" before
attempting to perform a connection. Make it so.

BUG=320574
TEST=net_unittests, chrome

Review URL: https://codereview.chromium.org/72043003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@236763 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 236763