Disable 0RTT if server and origin have different hosts.

net/quic/quic_stream_factory.h

Index: net/quic/quic_stream_factory.h
diff --git a/net/quic/quic_stream_factory.h b/net/quic/quic_stream_factory.h
index f3f7a71f33592cace70f9f41ad194db6da6e3032..57582d41ee11c135279aabaf78636066921fac51 100644
--- a/net/quic/quic_stream_factory.h
+++ b/net/quic/quic_stream_factory.h
@@ -58,6 +58,7 @@ class NET_EXPORT_PRIVATE QuicStreamRequest {
   int Request(const HostPortPair& host_port_pair,
               bool is_https,
               PrivacyMode privacy_mode,
+              base::StringPiece origin_host,
               base::StringPiece method,
               const BoundNetLog& net_log,
               const CompletionCallback& callback);
@@ -75,6 +76,7 @@ class NET_EXPORT_PRIVATE QuicStreamRequest {
  private:
   QuicStreamFactory* factory_;
   HostPortPair host_port_pair_;
+  std::string origin_host_;
   BoundNetLog net_log_;
   CompletionCallback callback_;
   scoped_ptr<QuicHttpStream> stream_;
@@ -122,6 +124,7 @@ class NET_EXPORT_PRIVATE QuicStreamFactory
   int Create(const HostPortPair& host_port_pair,
              bool is_https,
              PrivacyMode privacy_mode,
+             bool server_and_origin_have_same_host,
              base::StringPiece method,
              const BoundNetLog& net_log,
              QuicStreamRequest* request);
@@ -274,6 +277,8 @@ class NET_EXPORT_PRIVATE QuicStreamFactory
                                bool was_session_active);
 
   bool require_confirmation_;
+  // True iff server and origin have the same hostname.

[Ryan Hamilton, 2015/05/18 14:29:52]

nit: iff is not very common in comments. I think "if" is fine.

[Bence, 2015/05/18 15:17:55]

I am fine with not using iff if it is not common enough, but in that case, I
prefer to spell out "if and only if" to very specificly convey what I actually
mean.

BTW it is now moot in this file.

[Ryan Hamilton, 2015/05/18 16:21:54]

Yeah, I totally understand the sentiment. It seems, though, that "and only if"
is pretty much implicit in how if is used in comments. For example:

* True if this is a post request
* True if handshake confirmation is required
* True if QUIC is disabled
* True if QUIC was recently broken

All of these are really "iff" but for some reason it seems fine to leave them
out. 

Perhaps this is because programmers are lazy while mathematicians are precise?
:>

[Bence, 2015/05/18 18:12:02]

I totally agree.  However, it is not clear to me after all if you mind me
writing "if and only if", so I'll leave it as that for the time being.  Feel
free to ask me to change if you prefer.  Thanks.

+  bool server_and_origin_have_same_host_;

[Ryan Hamilton, 2015/05/18 14:29:52]

Wait, this is surprising. This is a member of the factory, not a job. That
doesn't seem right to me. The factory deal with lots of requests/sessions/jobs
at once. Which does this member apply to?

[Bence, 2015/05/18 15:17:55]

Good catch, sorry about that.  Done.

   HostResolver* host_resolver_;
   ClientSocketFactory* client_socket_factory_;
   base::WeakPtr<HttpServerProperties> http_server_properties_;