Do not mark QUIC as *broken* when a 0-RTT fails because this prevents us

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 272 matching lines @@
       break;
     }
   }
 }
 
 void HttpServerPropertiesImpl::SetBrokenAlternateProtocol(
     const HostPortPair& server) {
   AlternateProtocolMap::iterator it = alternate_protocol_map_.Get(server);
   if (it != alternate_protocol_map_.end()) {
     it->second.protocol = ALTERNATE_PROTOCOL_BROKEN;
-    return;
+  } else {
+    PortAlternateProtocolPair alternate;
+    alternate.protocol = ALTERNATE_PROTOCOL_BROKEN;
+    alternate_protocol_map_.Put(server, alternate);
   }
-  PortAlternateProtocolPair alternate;
-  alternate.protocol = ALTERNATE_PROTOCOL_BROKEN;
-  alternate_protocol_map_.Put(server, alternate);
-
   int count = ++broken_alternate_protocol_map_[server];
   base::TimeDelta delay =
       base::TimeDelta::FromSeconds(kBrokenAlternateProtocolDelaySecs);
   BrokenAlternateProtocolEntry entry;
   entry.server = server;
   entry.when = base::TimeTicks::Now() + delay * (1 << (count - 1));
   broken_alternate_protocol_list_.push_back(entry);
   // If this is the only entry in the list, schedule an expiration task.
   // Otherwse it will be rescheduled automatically when the pending
   // task runs.
@@ skipping 136 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