Change |use_alternative_service| not to disable Alternate Protocols.

net/http/http_stream_factory_impl.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_impl.h"
 
 #include <string>
 
 #include "base/logging.h"
 #include "base/stl_util.h"
@@ skipping 134 matching lines @@
   preconnect_job_set_.insert(job);
   job->Preconnect(num_streams);
 }
 
 const HostMappingRules* HttpStreamFactoryImpl::GetHostMappingRules() const {
   return session_->params().host_mapping_rules;
 }
 
 AlternativeServiceVector HttpStreamFactoryImpl::GetAlternativeServicesFor(
     const GURL& original_url) {
-  if (!session_->params().use_alternative_services)
-    return AlternativeServiceVector();
-
   if (original_url.SchemeIs("ftp"))
     return AlternativeServiceVector();
 
   HostPortPair origin = HostPortPair::FromURL(original_url);
   HttpServerProperties& http_server_properties =
       *session_->http_server_properties();
   const AlternativeServiceVector alternative_service_vector =
       http_server_properties.GetAlternativeServices(origin);
   if (alternative_service_vector.empty())
     return AlternativeServiceVector();
 
+  const bool enable_different_host =
+      session_->params().use_alternative_services;
+
   AlternativeServiceVector enabled_alternative_service_vector;
   for (const AlternativeService& alternative_service :
        alternative_service_vector) {
     DCHECK(IsAlternateProtocolValid(alternative_service.protocol));
     if (http_server_properties.IsAlternativeServiceBroken(
             alternative_service)) {
       HistogramAlternateProtocolUsage(ALTERNATE_PROTOCOL_USAGE_BROKEN);
       continue;
     }
 
+    if (origin.host() != alternative_service.host && !enable_different_host)
+      continue;
+
     // Some shared unix systems may have user home directories (like
     // http://foo.com/~mike) which allow users to emit headers.  This is a bad
     // idea already, but with Alternate-Protocol, it provides the ability for a
     // single user on a multi-user system to hijack the alternate protocol.
     // These systems also enforce ports <1024 as restricted ports.  So don't
     // allow protocol upgrades to user-controllable ports.
     const int kUnrestrictedPort = 1024;
     if (!session_->params().enable_user_alternate_protocol_ports &&
         (alternative_service.port >= kUnrestrictedPort &&
          origin.port() < kUnrestrictedPort))
@@ skipping 85 matching lines @@
   delete job;
 }
 
 void HttpStreamFactoryImpl::OnPreconnectsComplete(const Job* job) {
   preconnect_job_set_.erase(job);
   delete job;
   OnPreconnectsCompleteInternal();
 }
 
 }  // namespace net