Take the Extension Storage API out of experimental.

chrome/common/extensions/extension_permission_set.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 CHROME_COMMON_EXTENSIONS_EXTENSION_PERMISSION_SET_H_
 #define CHROME_COMMON_EXTENSIONS_EXTENSION_PERMISSION_SET_H_
 #pragma once
 
 #include <map>
 #include <set>
@@ skipping 102 matching lines @@
     kIme,
     kInputMethodPrivate,
     kManagement,
     kMediaPlayerPrivate,
     kMetricsPrivate,
     kNotification,
     kPageCapture,
     kPlugin,
     kProxy,
     kSocket,
+    kStorage,
     kSystemPrivate,
     kTab,
     kTerminalPrivate,
     kTts,
     kTtsEngine,
     kUnlimitedStorage,
     kWebNavigation,
     kWebRequest,
     kWebRequestBlocking,
     kWebSocketProxyPrivate,
@@ skipping 339 matching lines @@
 
   // The list of hosts that can be scripted by content scripts.
   // TODO(jstritar): Rename to "user_script_hosts_"?
   URLPatternSet scriptable_hosts_;
 
   // The list of hosts this effectively grants access to.
   URLPatternSet effective_hosts_;
 };
 
 #endif  // CHROME_COMMON_EXTENSIONS_EXTENSION_PERMISSION_SET_H_