[Extensions] DCHECK that ExtensionFunctions respond (and only once)

extensions/browser/api/socket/udp_socket.cc

 // Copyright 2014 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 "extensions/browser/api/socket/udp_socket.h"
 
 #include <algorithm>
 
+#include "base/callback_helpers.h"
 #include "base/lazy_instance.h"
 #include "extensions/browser/api/api_resource.h"
 #include "net/base/ip_address.h"
 #include "net/base/ip_endpoint.h"
 #include "net/base/net_errors.h"
 #include "net/udp/datagram_socket.h"
 #include "net/udp/udp_client_socket.h"
 
 namespace extensions {
 
@@ skipping 57 matching lines @@
   result = socket_.Bind(ip_end_point);
   if (result != net::OK)
     socket_.Close();
   return result;
 }
 
 void UDPSocket::Disconnect() {
   is_connected_ = false;
   socket_.Close();
   read_callback_.Reset();
-  recv_from_callback_.Reset();
+  // TODO(devlin): Should we do this for all callbacks?
+  if (!recv_from_callback_.is_null()) {
+    base::ResetAndReturn(&recv_from_callback_)
+        .Run(net::ERR_CONNECTION_CLOSED, nullptr, std::string(), 0);
+  }
   send_to_callback_.Reset();
   multicast_groups_.clear();
 }
 
 void UDPSocket::Read(int count, const ReadCompletionCallback& callback) {
   DCHECK(!callback.is_null());
 
   if (!read_callback_.is_null()) {
     callback.Run(net::ERR_IO_PENDING, NULL);
     return;
@@ skipping 201 matching lines @@
 
 ResumableUDPSocket::ResumableUDPSocket(const std::string& owner_extension_id)
     : UDPSocket(owner_extension_id),
       persistent_(false),
       buffer_size_(0),
       paused_(false) {}
 
 bool ResumableUDPSocket::IsPersistent() const { return persistent(); }
 
 }  // namespace extensions