Fixes crash bug when iterating through sessions in OnNetworkConnected.

net/quic/chromium/quic_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/quic/chromium/quic_stream_factory.h"
 
 #include <openssl/aead.h>
 
 #include <algorithm>
 #include <tuple>
@@ skipping 1247 matching lines @@
 void QuicStreamFactory::OnIPAddressChanged() {
   status_ = OPEN;
   CloseAllSessions(ERR_NETWORK_CHANGED, QUIC_IP_ADDRESS_CHANGED);
   set_require_confirmation(true);
 }
 
 void QuicStreamFactory::OnNetworkConnected(NetworkHandle network) {
   status_ = OPEN;
   ScopedConnectionMigrationEventLog scoped_event_log(net_log_,
                                                      "OnNetworkConnected");
-  for (auto session : all_sessions_) {
-    session.first->OnNetworkConnected(network, scoped_event_log.net_log());
+  QuicStreamFactory::SessionIdMap::iterator it = all_sessions_.begin();
+  // Sessions may be deleted while iterating through the map.
+  while (it != all_sessions_.end()) {
+    QuicChromiumClientSession* session = it->first;
+    ++it;
+    session->OnNetworkConnected(network, scoped_event_log.net_log());
   }
 }
 
 void QuicStreamFactory::OnNetworkMadeDefault(NetworkHandle network) {
   ScopedConnectionMigrationEventLog scoped_event_log(net_log_,
                                                      "OnNetworkMadeDefault");
   DCHECK_NE(NetworkChangeNotifier::kInvalidNetworkHandle, network);
   MaybeMigrateOrCloseSessions(network, /*close_if_cannot_migrate=*/false,
                               scoped_event_log.net_log());
   set_require_confirmation(true);
@@ skipping 586 matching lines @@
   // Since the session was active, there's no longer an
   // HttpStreamFactoryImpl::Job running which can mark it broken, unless the TCP
   // job also fails. So to avoid not using QUIC when we otherwise could, we mark
   // it as recently broken, which means that 0-RTT will be disabled but we'll
   // still race.
   http_server_properties_->MarkAlternativeServiceRecentlyBroken(
       alternative_service);
 }
 
 }  // namespace net