Update from https://crrev.com/315085

net/http/http_stream_factory.cc

 // 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.
 
 #include "net/http/http_stream_factory.h"
 
 #include "base/logging.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_split.h"
 #include "base/strings/string_util.h"
@@ skipping 68 matching lines @@
   }
 
   if (protocol == UNINITIALIZED_ALTERNATE_PROTOCOL)
     return;
 
   HostPortPair host_port(http_host_port_pair);
   const HostMappingRules* mapping_rules = GetHostMappingRules();
   if (mapping_rules)
     mapping_rules->RewriteHost(&host_port);
 
-  if (http_server_properties->HasAlternateProtocol(host_port)) {
-    const AlternateProtocolInfo existing_alternate =
-        http_server_properties->GetAlternateProtocol(host_port);
-    // If we think the alternate protocol is broken, don't change it.
-    if (existing_alternate.is_broken)
-      return;
-  }
-
   http_server_properties->SetAlternateProtocol(
       host_port, static_cast<uint16>(port), protocol, probability);
 }
 
 GURL HttpStreamFactory::ApplyHostMappingRules(const GURL& url,
                                               HostPortPair* endpoint) {
   const HostMappingRules* mapping_rules = GetHostMappingRules();
   if (mapping_rules && mapping_rules->RewriteHost(endpoint)) {
     url::Replacements<char> replacements;
     const std::string port_str = base::IntToString(endpoint->port());
     replacements.SetPort(port_str.c_str(), url::Component(0, port_str.size()));
     replacements.SetHost(endpoint->host().c_str(),
                          url::Component(0, endpoint->host().size()));
     return url.ReplaceComponents(replacements);
   }
   return url;
 }
 
 HttpStreamFactory::HttpStreamFactory() {}
 
 }  // namespace net