Race preconnects to HTTP2 proxies that support alternate proxies

net/http/http_network_session.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_NETWORK_SESSION_H_
 #define NET_HTTP_HTTP_NETWORK_SESSION_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 189 matching lines @@
     // Enable support for Token Binding.
     bool enable_token_binding;
 
     // Enable HTTP/0.9 for HTTP/HTTPS on ports other than the default one for
     // each protocol.
     bool http_09_on_non_default_ports_enabled;
 
     // If true, only one pending preconnect is allowed to proxies that support
     // request priorities.
     bool restrict_to_one_preconnect_for_proxies;
+    // If true, preconnect jobs to HTTP2 proxies are raced with an alternative
+    // job if the proxy supports an alternative proxy.
+    bool race_preconnects_to_http2_proxies;
   };
 
   enum SocketPoolType {
     NORMAL_SOCKET_POOL,
     WEBSOCKET_SOCKET_POOL,
     NUM_SOCKET_POOL_TYPES
   };
 
   explicit HttpNetworkSession(const Params& params);
   ~HttpNetworkSession() override;
@@ skipping 75 matching lines @@
 
   // Dumps memory allocation stats. |parent_dump_absolute_name| is the name
   // used by the parent MemoryAllocatorDump in the memory dump hierarchy.
   void DumpMemoryStats(base::trace_event::ProcessMemoryDump* pmd,
                        const std::string& parent_absolute_name) const;
 
   // Evaluates if QUIC is enabled for new streams.
   bool IsQuicEnabled() const;
 
   // Disable QUIC for new streams.
   void DisableQuic();

[Ryan Hamilton, 2017/01/24 19:36:59]

nit: it's best to upload Rebase patch sets independently from functional changes
so that it's easier for reviewers to compare two patch sets and see just what
changed. Not a big deal of course, but it's handy.

 
  private:
   friend class HttpNetworkSessionPeer;
 
   ClientSocketPoolManager* GetSocketPoolManager(SocketPoolType pool_type);
 
   // Flush sockets on low memory notifications callback.
   void OnMemoryPressure(
       base::MemoryPressureListener::MemoryPressureLevel memory_pressure_level);
 
@@ skipping 25 matching lines @@
   NextProtoVector next_protos_;
 
   Params params_;
 
   std::unique_ptr<base::MemoryPressureListener> memory_pressure_listener_;
 };
 
 }  // namespace net
 
 #endif  // NET_HTTP_HTTP_NETWORK_SESSION_H_