Revert of Move PseudoTCP and channel auth out of LibjingleTransportFactory. (patchset #5 id:100001 of https://codereview.chromium.org/551173004/)

Reason for revert:
Failed to compile on android builder.

http://build.chromium.org/p/chromium.webkit/builders/Android%20Builder/builds/46485

In file included from ../../remoting/protocol/pseudotcp_channel_factory.h:11:0,
                 from ../../remoting/protocol/pseudotcp_channel_factory.cc:5:
../../remoting/protocol/stream_channel_factory.h:34:41:error: 'string' in namespace 'std' does not name a type
   virtual void CreateChannel(const std::string& name,
                                         ^
../../remoting/protocol/stream_channel_factory.h:40:49:error: 'string' in namespace 'std' does not name a type
   virtual void CancelChannelCreation(const std::string& name) = 0;
...

Original issue's description:
> Move PseudoTCP and channel auth out of LibjingleTransportFactory.
>
> Previously TransportFactory interface was responsible for creation
> and initialization of several protocol layers, including PseudoTCP and
> authentication (TLS). Simplified it so now it only creates raw datagram
> transport channel. PseudoTcpChannelFactory is now responsible for
> setting up PseudoTcpAdapter and AuthenticatingChannelFactory takes care
> of channel authentication. Also added DatagramChannelFactory for
> Datagram channels.
>
> This change will make it possible to replace PseudoTcpChannelFactory
> with an object that creates SCTP-based channels.
>
> Also fixed a bug in SslHmacChannelAuthenticator. It wasn't working
> properly when deleted from the callback. (base::Callback objects
> shouldn't be deleted while being called because when deleted they
> also destroy reference parameters values they are holding).
>
> BUG=402993
>
> Committed: https://crrev.com/28d886c967e016a5d5812be43cd5916f577c2e10
> Cr-Commit-Position: refs/heads/master@{#294474}

TBR=wez@chromium.org,sergeyu@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=402993

Review URL: https://codereview.chromium.org/570463002

Cr-Commit-Position: refs/heads/master@{#294488}