Put the pop-up app launcher behind a compile-time flag, and provide defines.

chrome/browser/extensions/component_loader.cc

 // 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.
 
 #include "chrome/browser/extensions/component_loader.h"
 
 #include "base/command_line.h"
 #include "base/file_util.h"
 #include "base/json/json_string_value_serializer.h"
 #include "base/path_service.h"
@@ skipping 350 matching lines @@
 #if defined(OFFICIAL_BUILD)
   if (browser_defaults::enable_help_app) {
     Add(IDR_HELP_MANIFEST,
         FilePath(FILE_PATH_LITERAL("/usr/share/chromeos-assets/helpapp")));
   }
 #endif
 #endif  // !defined(OS_CHROMEOS)
 
   Add(IDR_WEBSTORE_MANIFEST, FilePath(FILE_PATH_LITERAL("web_store")));
 
-#if defined(OS_WIN)
+#if defined(ENABLE_SETTINGS_APP)
   Add(IDR_SETTINGS_APP_MANIFEST, FilePath(FILE_PATH_LITERAL("settings_app")));
 #endif
 
 #if !defined(OS_CHROMEOS)
   // Cloud Print component app. Not required on Chrome OS.
   Add(IDR_CLOUDPRINT_MANIFEST, FilePath(FILE_PATH_LITERAL("cloud_print")));
 #endif
 
 #if defined(OS_CHROMEOS)
   // Register access extensions only if accessibility is enabled.
@@ skipping 27 matching lines @@
 void ComponentLoader::RegisterUserPrefs(PrefService* prefs) {
   prefs->RegisterStringPref(prefs::kEnterpriseWebStoreURL,
                             std::string() /* default_value */,
                             PrefService::UNSYNCABLE_PREF);
   prefs->RegisterStringPref(prefs::kEnterpriseWebStoreName,
                             std::string() /* default_value */,
                             PrefService::UNSYNCABLE_PREF);
 }
 
 }  // namespace extensions