Make it possible to disable udev in linux

content/browser/browser_main_loop.h

 // 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.
 
 #ifndef CONTENT_BROWSER_BROWSER_MAIN_LOOP_H_
 #define CONTENT_BROWSER_BROWSER_MAIN_LOOP_H_
 
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 123 matching lines @@
   // user_input_monitor_ has to outlive audio_manager_, so declared first.
   scoped_ptr<media::UserInputMonitor> user_input_monitor_;
   scoped_ptr<media::AudioManager> audio_manager_;
   scoped_ptr<media::MIDIManager> midi_manager_;
   scoped_ptr<AudioMirroringManager> audio_mirroring_manager_;
   scoped_ptr<MediaStreamManager> media_stream_manager_;
   // Per-process listener for online state changes.
   scoped_ptr<BrowserOnlineStateObserver> online_state_observer_;
 #if defined(OS_WIN)
   scoped_ptr<SystemMessageWindowWin> system_message_window_;
-#elif defined(OS_LINUX)
+#elif defined(USE_UDEV)
   scoped_ptr<DeviceMonitorLinux> device_monitor_linux_;
 #elif defined(OS_MACOSX) && !defined(OS_IOS)
   scoped_ptr<DeviceMonitorMac> device_monitor_mac_;
 #endif
   // The startup task runner is created by CreateStartupTasks()
   scoped_ptr<StartupTaskRunner> startup_task_runner_;
 
   // Destroy parts_ before main_message_loop_ (required) and before other
   // classes constructed in content (but after main_thread_).
   scoped_ptr<BrowserMainParts> parts_;
@@ skipping 17 matching lines @@
   scoped_ptr<MemoryObserver> memory_observer_;
   scoped_ptr<base::debug::TraceMemoryController> trace_memory_controller_;
   scoped_ptr<base::debug::TraceEventSystemStatsMonitor> system_stats_monitor_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowserMainLoop);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_BROWSER_MAIN_LOOP_H_