Throttle HttpStreamFactoryImpl::Job to HTTP/2-supported servers

net/http/http_stream_factory_impl_job.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef NET_HTTP_HTTP_STREAM_FACTORY_IMPL_JOB_H_
 #define NET_HTTP_HTTP_STREAM_FACTORY_IMPL_JOB_H_
 
 #include <memory>
 #include <utility>
 
@@ skipping 251 matching lines @@
     // resumes the main job.
     //
     // A QUIC alternative job notifies the JobController in DoInitConnection
     // regardless of whether it pools to an existing QUIC session, but the main
     // job is only resumed after some delay.
     //
     // If the main job is resumed, then it races the alternative job.
     STATE_WAIT,
     STATE_WAIT_COMPLETE,
 
+    STATE_BEFORE_INIT_CONNECTION,

[Ryan Hamilton, 2017/06/12 13:30:49]

nit: Instead of "before init connection" there there a term that might be more
self-explanatory? Maybe something about "throttling" or "evaluate_throttle"?

[xunjieli, 2017/06/13 15:23:10]

Done.

     STATE_INIT_CONNECTION,
     STATE_INIT_CONNECTION_COMPLETE,
     STATE_WAITING_USER_ACTION,
     STATE_RESTART_TUNNEL_AUTH,
     STATE_RESTART_TUNNEL_AUTH_COMPLETE,
     STATE_CREATE_STREAM,
     STATE_CREATE_STREAM_COMPLETE,
     STATE_DRAIN_BODY_FOR_AUTH_RESTART,
     STATE_DRAIN_BODY_FOR_AUTH_RESTART_COMPLETE,
     STATE_DONE,
@@ skipping 24 matching lines @@
   int StartInternal();
   int DoInitConnectionImpl();
 
   // Each of these methods corresponds to a State value.  Those with an input
   // argument receive the result from the previous state.  If a method returns
   // ERR_IO_PENDING, then the result from OnIOComplete will be passed to the
   // next state method as the result arg.
   int DoStart();
   int DoWait();
   int DoWaitComplete(int result);
+  int DoBeforeInitConnection();
+  int DoBeforeInitConnectionComplete(int result);
   int DoInitConnection();
   int DoInitConnectionComplete(int result);
   int DoWaitingUserAction(int result);
   int DoCreateStream();
   int DoCreateStreamComplete(int result);
   int DoRestartTunnelAuth();
   int DoRestartTunnelAuthComplete(int result);
 
+  void ResumeInitConnection();
   // Creates a SpdyHttpStream or a BidirectionalStreamImpl from the given values
   // and sets to |stream_| or |bidirectional_stream_impl_| respectively. Does
   // nothing if |stream_factory_| is for WebSockets.
   int SetSpdyHttpStreamOrBidirectionalStreamImpl(
       base::WeakPtr<SpdySession> session,
       bool direct);
 
   // Returns to STATE_INIT_CONNECTION and resets some state.
   void ReturnToStateInitConnection(bool close_connection);
 
@@ skipping 139 matching lines @@
   // True if not connecting to an Https proxy for an Http url.
   const bool spdy_session_direct_;
 
   const SpdySessionKey spdy_session_key_;
 
   base::TimeTicks job_stream_ready_start_time_;
 
   // Type of stream that is requested.
   HttpStreamRequest::StreamType stream_type_;
 
+  // Whether the Job should continue to DoInitConnection().

[Bence, 2017/06/09 19:17:38]

Isn't it rather whether the Job has already continued to DoInitConnection() so
that it should not try to do it again?

[xunjieli, 2017/06/13 15:23:10]

Done.

+  bool resumed_init_connection_;

[Bence, 2017/06/09 19:17:38]

Optional: init_connection_already_resumed_.

[xunjieli, 2017/06/13 15:23:10]

Done.

+
   base::WeakPtrFactory<Job> ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(Job);
 };
 
 // Factory for creating Jobs.
 class HttpStreamFactoryImpl::JobFactory {
  public:
   JobFactory();
 
@@ skipping 40 matching lines @@
       HostPortPair destination,
       GURL origin_url,
       const ProxyServer& alternative_proxy_server,
       bool enable_ip_based_pooling,
       NetLog* net_log);
 };
 
 }  // namespace net
 
 #endif  // NET_HTTP_HTTP_STREAM_FACTORY_IMPL_JOB_H_