Remove unused code and exclude unused files on Chrome OS too.

net/base/network_change_notifier_linux.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.
 //
 // This implementation of NetworkChangeNotifier's offline state detection
 // depends on D-Bus and NetworkManager, and is known to work on at least
 // GNOME version 2.30.  If D-Bus or NetworkManager are unavailable, this
 // implementation will always behave as if it is online.
 
 #include "net/base/network_change_notifier_linux.h"
@@ skipping 366 matching lines @@
     int /* fd */) {
   NOTREACHED();
 }
 
 void NetworkChangeNotifierLinux::Thread::ListenForNotifications() {
   char buf[4096];
   int rv = ReadNotificationMessage(buf, arraysize(buf));
   while (rv > 0) {
     if (HandleNetlinkMessage(buf, rv)) {
       VLOG(1) << "Detected IP address changes.";
-#if defined(OS_CHROMEOS)
-      // TODO(oshima): chromium-os:8285 - introduced artificial delay to
-      // work around the issue of network load issue after connection
-      // restored. See the bug for more details.
-      //  This should be removed once this bug is properly fixed.
-      const int kObserverNotificationDelayMS = 200;
-      message_loop()->PostDelayedTask(
-          FROM_HERE,
-          base::Bind(&NetworkChangeNotifier::NotifyObserversOfIPAddressChange),
-          kObserverNotificationDelayMS);
-#else
       NotifyObserversOfIPAddressChange();
-#endif
     }
     rv = ReadNotificationMessage(buf, arraysize(buf));
   }
 
   if (rv == ERR_IO_PENDING) {
     rv = MessageLoopForIO::current()->WatchFileDescriptor(netlink_fd_, false,
         MessageLoopForIO::WATCH_READ, &netlink_watcher_, this);
     LOG_IF(ERROR, !rv) << "Failed to watch netlink socket: " << netlink_fd_;
   }
 }
@@ skipping 39 matching lines @@
   // Stopping from here allows us to sanity- check that the notifier
   // thread shut down properly.
   notifier_thread_->Stop();
 }
 
 bool NetworkChangeNotifierLinux::IsCurrentlyOffline() const {
   return notifier_thread_->IsCurrentlyOffline();
 }
 
 }  // namespace net