Fix the build when use_glib is set to 0.

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 668 matching lines @@
 #if defined(OS_WIN)
 void MessageLoopForUI::AddObserver(Observer* observer) {
   static_cast<MessagePumpWin*>(pump_.get())->AddObserver(observer);
 }
 
 void MessageLoopForUI::RemoveObserver(Observer* observer) {
   static_cast<MessagePumpWin*>(pump_.get())->RemoveObserver(observer);
 }
 #endif  // defined(OS_WIN)
 
-#if defined(USE_OZONE) || (defined(OS_CHROMEOS) && !defined(USE_GLIB))
+#if defined(USE_OZONE) || (defined(OS_CHROMEOS) && !defined(USE_GLIB)) || \
+    (defined(OS_LINUX) && !defined(USE_GLIB))
 bool MessageLoopForUI::WatchFileDescriptor(
     int fd,
     bool persistent,
     MessagePumpLibevent::Mode mode,
     MessagePumpLibevent::FileDescriptorWatcher *controller,
     MessagePumpLibevent::Watcher *delegate) {
   return static_cast<MessagePumpLibevent*>(pump_.get())->WatchFileDescriptor(
       fd,
       persistent,
       mode,
@@ skipping 41 matching lines @@
       persistent,
       mode,
       controller,
       delegate);
 }
 #endif
 
 #endif  // !defined(OS_NACL)
 
 }  // namespace base