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

net/spdy/chromium/spdy_session_pool.h

Index: net/spdy/chromium/spdy_session_pool.h
diff --git a/net/spdy/chromium/spdy_session_pool.h b/net/spdy/chromium/spdy_session_pool.h
index 613a3d9ed0301daaed4d6b7729cdc2262f5646ff..e3b8fc65768269a35e31d49ffabf89073cc3ec27 100644
--- a/net/spdy/chromium/spdy_session_pool.h
+++ b/net/spdy/chromium/spdy_session_pool.h
@@ -179,6 +179,17 @@ class NET_EXPORT SpdySessionPool
                              bool using_spdy,
                              NetLogSource source_dependency);
 
+  // Called when a HttpStreamRequest is started with |spdy_session_key|.
+  // Returns true if the request should continue. Returns false if the request
+  // should wait until |callback| is invoked before continuing.
+  bool StartRequest(const SpdySessionKey& spdy_session_key,

[Bence, 2017/06/09 19:17:40]

Optional: return OK instead of true and discard |callback|, or ERR_IO_PENDING
instead of false and call |callback| later, just like it's done elsewhere in the
network stack.

[xunjieli, 2017/06/13 15:23:11]

Acknowledged. But the callback is not a net::CompletionCallback. I will keep it
as it is so it's easier to think about the return value. Change it to return a
net_error code, the caller might add error handling code for non-OK and
non-ERR_IO_PENDING.

+                    const base::Closure& callback);
+
+  // Resumes all pending requests with |spdy_session_key|.
+  void ResumeAllPendingRequests(const SpdySessionKey& spdy_session_key);
+  // Resumes the next pending request with |spdy_session_key|.
+  void ResumeNextPendingRequest(const SpdySessionKey& spdy_session_key);

[Bence, 2017/06/09 19:17:40]

Do you think it is worth making this method private, or inlining it, since there
is only one call site?

[xunjieli, 2017/06/13 15:23:11]

Done.

+
   // Adds |request| to |spdy_session_request_map_| under |spdy_session_key| Key.
   // Sets |spdy_session_key| as |request|'s SpdySessionKey.
   void AddRequestToSpdySessionRequestMap(
@@ -271,7 +282,11 @@ class NET_EXPORT SpdySessionPool
   // and maximum HPACK dynamic table size.
   const SettingsMap initial_settings_;
 
+  // TODO(xunjieli): Merge these two.
   SpdySessionRequestMap spdy_session_request_map_;
+  typedef std::map<SpdySessionKey, std::list<base::Closure>>
+      SpdySessionPendingRequestMap;
+  SpdySessionPendingRequestMap spdy_session_pending_request_map_;
 
   TimeFunc time_func_;
   ServerPushDelegate* push_delegate_;