Plumb through NetworkChangeNotifier::IsOffline() to WebKit, enabling

net/base/network_change_notifier_win.cc

 // Copyright (c) 2010 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/base/network_change_notifier_win.h"
 
 #include <iphlpapi.h>
 #include <winsock2.h>
 
 #include "base/logging.h"
+#include "base/message_loop.h"
+#include "base/task.h"
 #include "net/base/winsock_init.h"
 
 #pragma comment(lib, "iphlpapi.lib")
 
 namespace net {
 
 NetworkChangeNotifierWin::NetworkChangeNotifierWin() {
   memset(&addr_overlapped_, 0, sizeof addr_overlapped_);
   addr_overlapped_.hEvent = WSACreateEvent();
   WatchForAddressChange();
@@ skipping 118 matching lines @@
   result = WSALookupServiceEnd(ws_handle);
   LOG_IF(ERROR, result != 0)
       << "WSALookupServiceEnd() failed with: " << result;
 
   return !found_connection;
 }
 
 void NetworkChangeNotifierWin::OnObjectSignaled(HANDLE object) {
   NotifyObserversOfIPAddressChange();
 
+  // Calling IsOffline() at this very moment is likely to give
+  // the wrong result, so we delay that until a little bit later.
+  //
+  // The one second delay chosen here was determined experimentally
+  // by adamk on Windows 7.
+  MessageLoop::current()->PostDelayedTask(

[eroman, 2011/03/01 05:23:10]

I suggest adding a bit to keep track of the outstanding task, and only allow 1
such task to be outstanding at a time.

You should be able to use the oneshottimer class and reset it to 1 second each
time.

This way we can avoid calling IsCurrentlyOffline() multiple times when lots of
activity is happening.

[adamk, 2011/03/01 19:20:06]

Thanks for the tip, replaced with a OneShotTimer.  The one slightly odd thing is
that we're now calling a static function as though it were an instance method,
but from my understanding that's guaranteed to work fine.

A side note: it looks like the only reason the Notify method is static is to
make it easy to call from unit tests.  In a followup change I might make these
instance methods just for clarity's sake.

+      FROM_HERE,
+      NewRunnableFunction(&NotifyObserversOfOnlineStateChange),
+      1000);
+
   // Start watching for the next address change.
   WatchForAddressChange();
 }
 
 void NetworkChangeNotifierWin::WatchForAddressChange() {
   HANDLE handle = NULL;
   DWORD ret = NotifyAddrChange(&handle, &addr_overlapped_);
   CHECK(ret == ERROR_IO_PENDING);
   addr_watcher_.StartWatching(addr_overlapped_.hEvent, this);
 }
 
 }  // namespace net