[CrOS Tether] TetherHostFetcher: When invoking callbacks, use a copy of the device list.

chromeos/components/tether/tether_host_fetcher.cc

 // Copyright 2017 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 "chromeos/components/tether/tether_host_fetcher.h"
 
 #include "base/bind.h"
 #include "base/memory/ptr_util.h"
 #include "components/cryptauth/cryptauth_device_manager.h"
 #include "components/cryptauth/remote_device_loader.h"
@@ skipping 67 matching lines @@
 
   // Make a copy of the requests to ensure that if one of the callbacks makes a
   // new fetch request, it does not affect the iteration of requests.
   std::vector<TetherHostFetchRequest> requests = requests_;
   requests_.clear();
 
   for (auto& request : requests) {
     if (request.device_id.empty()) {
       DCHECK(!request.list_callback.is_null());
 
-      request.list_callback.Run(remote_devices);
+      request.list_callback.Run(remote_devices_copy);
       continue;
     }
 
     DCHECK(!request.single_callback.is_null());
     bool has_run_callback = false;
     for (const auto& remote_device : remote_devices_copy) {
       if (request.device_id == remote_device.GetDeviceId()) {
         has_run_callback = true;
         request.single_callback.Run(
             base::MakeUnique<cryptauth::RemoteDevice>(remote_device));
         break;
       }
     }
 
     if (!has_run_callback) {
       request.single_callback.Run(nullptr);
     }
   }
 }
 
 }  // namespace tether
 
 }  // namespace chromeos