Remove the word "factory" from WebSocketChannel

The implementation of WebSocketChannel also contained some things
calling themselves stream factories. For completeness, rename them as
well.

BUG=316477
TEST=net_unittests --gtest_filter=WebSocketChannel*

Review URL: https://codereview.chromium.org/66013003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@234827 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 234827