Remove OnBeforeSocketStreamConnect()

NetworkDelegate::OnBeforeSocketStreamConnect() is not called by the new
WebSocket implementation.

Instead, the normal OnBeforeURLRequest() is called, permitted URL
blacklists to be applied as before.

Also remove a no-op #include of socket_stream.h from
chrome/test/chromedriver/net/sync_websocket_impl.h.

BUG=423201
TEST=browser_tests, unit_tests, chromedriver_tests

Review URL: https://codereview.chromium.org/671703002

Cr-Commit-Position: refs/heads/master@{#300842}