Revert of Remove support for Alt-Svc/Alternate Protocol Probability

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 61 matching lines @@
       if (!match_found) {
         continue;
       }
     }
     AlternativeService alternative_service(protocol,
                                            alternative_service_entry.host,
                                            alternative_service_entry.port);
     base::Time expiration =
         base::Time::Now() +
         base::TimeDelta::FromSeconds(alternative_service_entry.max_age);
-    AlternativeServiceInfo alternative_service_info(alternative_service,
-                                                    expiration);
+    AlternativeServiceInfo alternative_service_info(
+        alternative_service, alternative_service_entry.probability, expiration);
     alternative_service_info_vector.push_back(alternative_service_info);
   }
 
   http_server_properties->SetAlternativeServices(
       RewriteHost(http_host_port_pair), alternative_service_info_vector);
 }
 
 void HttpStreamFactory::ProcessAlternateProtocol(
     const base::WeakPtr<HttpServerProperties>& http_server_properties,
     const std::vector<std::string>& alternate_protocol_values,
     const HostPortPair& http_host_port_pair,
     const HttpNetworkSession& session) {
   AlternateProtocol protocol = UNINITIALIZED_ALTERNATE_PROTOCOL;
   int port = 0;
+  double probability = 1;
   bool is_valid = true;
   for (size_t i = 0; i < alternate_protocol_values.size(); ++i) {
     base::StringPiece alternate_protocol_str = alternate_protocol_values[i];
+    if (base::StartsWith(alternate_protocol_str, "p=",
+                         base::CompareCase::SENSITIVE)) {
+      if (!base::StringToDouble(alternate_protocol_str.substr(2).as_string(),
+                                &probability) ||
+          probability < 0 || probability > 1) {
+        DVLOG(1) << kAlternateProtocolHeader
+                 << " header has unrecognizable probability: "
+                 << alternate_protocol_values[i];
+        is_valid = false;
+        break;
+      }
+      continue;
+    }
+
     std::vector<base::StringPiece> port_protocol_vector =
         base::SplitStringPiece(alternate_protocol_str, ":",
                                base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL);
     if (port_protocol_vector.size() != 2) {
       DVLOG(1) << kAlternateProtocolHeader
                << " header has too many tokens: "
                << alternate_protocol_str;
       is_valid = false;
       break;
     }
@@ skipping 20 matching lines @@
   }
 
   if (!is_valid || protocol == UNINITIALIZED_ALTERNATE_PROTOCOL) {
     http_server_properties->ClearAlternativeServices(http_host_port_pair);
     return;
   }
 
   http_server_properties->SetAlternativeService(
       RewriteHost(http_host_port_pair),
       AlternativeService(protocol, "", static_cast<uint16_t>(port)),
-      base::Time::Now() + base::TimeDelta::FromDays(30));
+      probability, base::Time::Now() + base::TimeDelta::FromDays(30));
 }
 
 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::UintToString(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() {}
 
 HostPortPair HttpStreamFactory::RewriteHost(HostPortPair host_port_pair) {
   const HostMappingRules* mapping_rules = GetHostMappingRules();
   if (mapping_rules)
     mapping_rules->RewriteHost(&host_port_pair);
   return host_port_pair;
 }
 
 }  // namespace net