Add a probability to Alternate-Protocol support.

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"
 #include "base/strings/string_number_conversions.h"
 #include "net/base/net_log.h"
 #include "net/base/net_util.h"
 #include "net/http/http_network_session.h"
 #include "net/http/http_server_properties.h"
 #include "net/http/http_stream_factory_impl_job.h"
 #include "net/http/http_stream_factory_impl_request.h"
 #include "net/spdy/spdy_http_stream.h"
 #include "url/gurl.h"
 
 namespace net {
 
 namespace {
 
-const PortAlternateProtocolPair kNoAlternateProtocol = {
-  0,  UNINITIALIZED_ALTERNATE_PROTOCOL
-};
-
 GURL UpgradeUrlToHttps(const GURL& original_url, int port) {
   GURL::Replacements replacements;
   // new_sheme and new_port need to be in scope here because GURL::Replacements
   // references the memory contained by them directly.
   const std::string new_scheme = "https";
   const std::string new_port = base::IntToString(port);
   replacements.SetSchemeStr(new_scheme);
   replacements.SetPortStr(new_port);
   return original_url.ReplaceComponents(replacements);
 }
@@ skipping 65 matching lines @@
     WebSocketHandshakeStreamBase::CreateHelper*
         websocket_handshake_stream_create_helper,
     const BoundNetLog& net_log) {
   Request* request = new Request(request_info.url,
                                  this,
                                  delegate,
                                  websocket_handshake_stream_create_helper,
                                  net_log);
 
   GURL alternate_url;
-  PortAlternateProtocolPair alternate =
+  AlternateProtocolInfo alternate =
       GetAlternateProtocolRequestFor(request_info.url, &alternate_url);
   Job* alternate_job = NULL;
   if (alternate.protocol != UNINITIALIZED_ALTERNATE_PROTOCOL) {
     // Never share connection with other jobs for FTP requests.
     DCHECK(!request_info.url.SchemeIs("ftp"));
 
     HttpRequestInfo alternate_request_info = request_info;
     alternate_request_info.url = alternate_url;
     alternate_job =
         new Job(this, session_, alternate_request_info, priority,
@@ skipping 23 matching lines @@
 }
 
 void HttpStreamFactoryImpl::PreconnectStreams(
     int num_streams,
     const HttpRequestInfo& request_info,
     RequestPriority priority,
     const SSLConfig& server_ssl_config,
     const SSLConfig& proxy_ssl_config) {
   DCHECK(!for_websockets_);
   GURL alternate_url;
-  PortAlternateProtocolPair alternate =
+  AlternateProtocolInfo alternate =
       GetAlternateProtocolRequestFor(request_info.url, &alternate_url);
   Job* job = NULL;
   if (alternate.protocol != UNINITIALIZED_ALTERNATE_PROTOCOL) {
     HttpRequestInfo alternate_request_info = request_info;
     alternate_request_info.url = alternate_url;
     job = new Job(this, session_, alternate_request_info, priority,
                   server_ssl_config, proxy_ssl_config, session_->net_log());
     job->MarkAsAlternate(request_info.url, alternate);
   } else {
     job = new Job(this, session_, request_info, priority,
                   server_ssl_config, proxy_ssl_config, session_->net_log());
   }
   preconnect_job_set_.insert(job);
   job->Preconnect(num_streams);
 }
 
 const HostMappingRules* HttpStreamFactoryImpl::GetHostMappingRules() const {
   return session_->params().host_mapping_rules;
 }
 
-PortAlternateProtocolPair HttpStreamFactoryImpl::GetAlternateProtocolRequestFor(
+AlternateProtocolInfo HttpStreamFactoryImpl::GetAlternateProtocolRequestFor(
     const GURL& original_url,
     GURL* alternate_url) {
+  const AlternateProtocolInfo kNoAlternateProtocol =
+      AlternateProtocolInfo(0,  UNINITIALIZED_ALTERNATE_PROTOCOL, 0);
+
   if (!session_->params().use_alternate_protocols)
     return kNoAlternateProtocol;
 
   if (original_url.SchemeIs("ftp"))
     return kNoAlternateProtocol;
 
   HostPortPair origin = HostPortPair(original_url.HostNoBrackets(),
                                      original_url.EffectiveIntPort());
 
   HttpServerProperties& http_server_properties =
       *session_->http_server_properties();
   if (!http_server_properties.HasAlternateProtocol(origin))
     return kNoAlternateProtocol;
 
-  PortAlternateProtocolPair alternate =
+  AlternateProtocolInfo alternate =
       http_server_properties.GetAlternateProtocol(origin);
   if (alternate.protocol == ALTERNATE_PROTOCOL_BROKEN) {
     HistogramAlternateProtocolUsage(
         ALTERNATE_PROTOCOL_USAGE_BROKEN,
         http_server_properties.GetAlternateProtocolExperiment());
     return kNoAlternateProtocol;
   }
 
   if (!IsAlternateProtocolValid(alternate.protocol)) {
     NOTREACHED();
@@ skipping 95 matching lines @@
   delete job;
 }
 
 void HttpStreamFactoryImpl::OnPreconnectsComplete(const Job* job) {
   preconnect_job_set_.erase(job);
   delete job;
   OnPreconnectsCompleteInternal();
 }
 
 }  // namespace net