ozone: Protect X11-specific code in IME support

ui/base/ime/ime.gypi

 # 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.
 
 {
   'dependencies' : [
     '<(DEPTH)/ui/events/events.gyp:events',
   ],
   'sources': [
     'candidate_window.cc',
@@ skipping 92 matching lines @@
         'linux/fake_input_method_context_factory.h',
         'linux/linux_input_method_context.h',
         'linux/linux_input_method_context_factory.cc',
         'linux/linux_input_method_context_factory.h',
       ],
     }],
     ['use_x11==0', {
       'sources!': [
         'composition_text_util_pango.cc',
         'composition_text_util_pango.h',
+        'chromeos/character_composer.cc',
+        'chromeos/character_composer.h',
       ],
     }],
   ],
 }