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

net/base/network_change_notifier_win.cc

Index: net/base/network_change_notifier_win.cc
diff --git a/net/base/network_change_notifier_win.cc b/net/base/network_change_notifier_win.cc
index bc906cb8a61c32e115d9e7e1c665b83882f14680..e4e02c7f1d96312cfd442c1dfb587814ab91f184 100644
--- a/net/base/network_change_notifier_win.cc
+++ b/net/base/network_change_notifier_win.cc
@@ -8,6 +8,8 @@
 #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")
@@ -146,6 +148,16 @@ bool NetworkChangeNotifierWin::IsCurrentlyOffline() const {
 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();
 }