Compile File Manager Private API on Chrome OS only.

chrome/common/extensions/api/schemas.gypi

 # Copyright 2014 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.
 
 {
   'sources': [
     '<@(schema_files)',
   ],
   'variables': {
     'main_schema_files': [
@@ skipping 21 matching lines @@
       'data_reduction_proxy.json',
       'debugger.json',
       'desktop_capture.json',
       'developer_private.idl',
       'dial.idl',
       'downloads.idl',
       'downloads_internal.idl',
       'easy_unlock_private.idl',
       'experience_sampling_private.json',
       'feedback_private.idl',
-      'file_manager_private.idl',
-      'file_manager_private_internal.idl',
       'file_system.idl',
       'font_settings.json',
       'gcd_private.idl',
       'gcm.json',
       'hangouts_private.idl',
       'history.json',
       'hotword_private.idl',
       'i18n.json',
       'identity.idl',
       'identity_private.idl',
@@ skipping 44 matching lines @@
       'top_sites.json',
     ],
 
     # ChromeOS-specific schemas.
     'chromeos_schema_files': [
       'echo_private.json',
       'enterprise_platform_keys.idl',
       'enterprise_platform_keys_internal.idl',
       'enterprise_platform_keys_private.json',
       'file_browser_handler_internal.json',
+      'file_manager_private.idl',
+      'file_manager_private_internal.idl',
       'file_system_provider.idl',
       'file_system_provider_internal.idl',
       'first_run_private.json',
       'input_ime.json',
       'launcher_search_provider.idl',
       'log_private.idl',
       'platform_keys.idl',
       'platform_keys_internal.idl',
       'terminal_private.json',
       'wallpaper.json',
@@ skipping 40 matching lines @@
         'schema_files': [
           '<@(webrtc_schema_files)',
         ],
       }],
     ],
     'cc_dir': 'chrome/common/extensions/api',
     'root_namespace': 'extensions::api::%(namespace)s',
     'impl_dir_': 'chrome/browser/extensions/api',
   },
 }