Modify SetAlternateProtocol and HasAlternateProtocol behavior.

net/http/http_server_properties_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_server_properties_impl.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop/message_loop.h"
@@ skipping 264 matching lines @@
 
 void HttpServerPropertiesImpl::SetAlternateProtocol(
     const HostPortPair& server,
     uint16 alternate_port,
     AlternateProtocol alternate_protocol,
     double alternate_probability) {
 
   AlternateProtocolInfo alternate(alternate_port,
                                   alternate_protocol,
                                   alternate_probability);
-  if (HasAlternateProtocol(server)) {
-    const AlternateProtocolInfo existing_alternate =
-        GetAlternateProtocol(server);
+  // Do not call HasAlternateProtocol(), because we do not care about
+  // |g_forced_alternate_protocol|, or whether the alternate protocol
+  // probability is higher than the threshold.
+  AlternateProtocolMap::iterator it = alternate_protocol_map_.Get(server);
+  if (it == alternate_protocol_map_.end()) {
+    const CanonicalHostMap::const_iterator canonical_host =
+        GetCanonicalHost(server);
+    if (canonical_host != canonical_host_to_origin_map_.end()) {
+      it = alternate_protocol_map_.Get(canonical_host->second);
+    }
+  }

[Ryan Hamilton, 2015/01/16 22:42:45]

This looks like a good change. I wonder if this should go into a method of some
sort. I suspect we do something similar elsewhere in the code?

[Bence, 2015/01/23 16:45:58]

Done.

+  if (it != alternate_protocol_map_.end()) {
+    const AlternateProtocolInfo existing_alternate = it->second;
 
     if (existing_alternate.is_broken) {
       DVLOG(1) << "Ignore alternate protocol since it's known to be broken.";
       return;
     }
 
     if (!existing_alternate.Equals(alternate)) {
       LOG(WARNING) << "Changing the alternate protocol for: "
                    << server.ToString()
                    << " from [Port: " << existing_alternate.port
@@ skipping 230 matching lines @@
   base::TimeDelta delay = when > now ? when - now : base::TimeDelta();
   base::MessageLoop::current()->PostDelayedTask(
       FROM_HERE,
       base::Bind(
           &HttpServerPropertiesImpl::ExpireBrokenAlternateProtocolMappings,
           weak_ptr_factory_.GetWeakPtr()),
       delay);
 }
 
 }  // namespace net