x11: Make the event-source work with both glib and libevent message-pumps.

base/message_loop/message_loop.cc

 // Copyright 2013 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 "base/message_loop/message_loop.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/compiler_specific.h"
@@ skipping 652 matching lines @@
 #if !defined(OS_NACL) && defined(OS_WIN)
 void MessageLoopForUI::AddObserver(Observer* observer) {
   pump_ui()->AddObserver(observer);
 }
 
 void MessageLoopForUI::RemoveObserver(Observer* observer) {
   pump_ui()->RemoveObserver(observer);
 }
 #endif  // !defined(OS_NACL) && defined(OS_WIN)
 
-#if defined(USE_OZONE) && !defined(OS_NACL)
+#if !defined(OS_NACL) && \
+    (defined(USE_OZONE) || (defined(OS_CHROMEOS) && !defined(USE_GLIB)))
 bool MessageLoopForUI::WatchFileDescriptor(
     int fd,
     bool persistent,
     MessagePumpLibevent::Mode mode,
     MessagePumpLibevent::FileDescriptorWatcher *controller,
     MessagePumpLibevent::Watcher *delegate) {
   return pump_libevent()->WatchFileDescriptor(
       fd,
       persistent,
       mode,
@@ skipping 45 matching lines @@
       fd,
       persistent,
       mode,
       controller,
       delegate);
 }
 
 #endif
 
 }  // namespace base