Allow at most one preconnect to HTTP2 proxy servers

net/http/http_stream_factory_impl.h

Index: net/http/http_stream_factory_impl.h
diff --git a/net/http/http_stream_factory_impl.h b/net/http/http_stream_factory_impl.h
index 92301356d30b261ead4cf7f2b4ff12dbff8cf9c7..99aaf2206455e00c6fdfd20100c1e927238f0d73 100644
--- a/net/http/http_stream_factory_impl.h
+++ b/net/http/http_stream_factory_impl.h
@@ -25,6 +25,7 @@
 namespace net {
 
 class HttpNetworkSession;
+class ProxyInfo;
 class SpdySession;
 class NetLogWithSource;
 
@@ -129,6 +130,19 @@ class NET_EXPORT_PRIVATE HttpStreamFactoryImpl : public HttpStreamFactory {
   // from |job_controller_set_|.
   void OnJobControllerComplete(JobController* controller);
 
+  // Returns true if a connection to the proxy server contained in |proxy_info|
+  // can be skipped by a job controlled by |controller|.
+  bool OnInitConnection(const JobController& controller,
+                        const ProxyInfo& proxy_info);
+
+  // Notifies |this| that a stream to the proxy server contained in |proxy_info|
+  // is ready.
+  void OnStreamReady(const ProxyInfo& proxy_info);
+
+  // Returns true if |proxy_info| contains a proxy server that supports request
+  // priorities.
+  bool ProxyServerSupportsPriorities(const ProxyInfo& proxy_info) const;
+
   HttpNetworkSession* const session_;
 
   // All Requests are handed out to clients. By the time HttpStreamFactoryImpl
@@ -146,9 +160,18 @@ class NET_EXPORT_PRIVATE HttpStreamFactoryImpl : public HttpStreamFactory {
   // Factory used by job controllers for creating jobs.
   std::unique_ptr<JobFactory> job_factory_;
 
+  // Set of proxy servers that support request priorities to which subsequent
+  // preconnects should be skipped.
+  std::set<ProxyServer> preconnecting_proxy_servers_;
+
   SpdySessionRequestMap spdy_session_request_map_;
 
   const bool for_websockets_;
+
+  // True if only one preconnect is allowed to proxy servers that support
+  // request priorities.
+  const bool allow_only_one_preconnect_to_proxy_servers_;
+
   DISALLOW_COPY_AND_ASSIGN(HttpStreamFactoryImpl);
 };