Move kEnableExperimentalExtensionApis switch to extensions/common/switches.cc.

extensions/common/switches.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 "extensions/common/switches.h"
 
 namespace extensions {
 
 namespace switches {
 
 // Allows the browser to load extensions that lack a modern manifest when that
 // would otherwise be forbidden.
 const char kAllowLegacyExtensionManifests[] =
     "allow-legacy-extension-manifests";
 
 // Allows injecting extensions and user scripts on the extensions gallery
 // site. Normally prevented for security reasons, but can be useful for
 // automation testing of the gallery.
 const char kAllowScriptingGallery[]         = "allow-scripting-gallery";
 
+// Enables extension APIs that are in development.
+const char kEnableExperimentalExtensionApis[] =
+    "enable-experimental-extension-apis";
+
 // Enables extensions running scripts on chrome:// URLs.
 // Extensions still need to explicitly request access to chrome:// URLs in the
 // manifest.
 const char kExtensionsOnChromeURLs[]        = "extensions-on-chrome-urls";
 
 // Makes component extensions appear in chrome://settings/extensions.
 const char kShowComponentExtensionOptions[] =
     "show-component-extension-options";
 
 }  // namespace switches
 
 }  // namespace extensions