Take the Extension Storage API out of experimental.

chrome/renderer/resources/extensions/storage_custom_bindings.js

 // 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.
 
-// Custom bindings for the experimental.storage API.
+// Custom bindings for the storage API.
 
 (function() {
 
 native function GetChromeHidden();
 
 var chromeHidden = GetChromeHidden();
 
 chromeHidden.registerCustomType('StorageNamespace',
     function(typesAPI) {
   var sendRequest = typesAPI.sendRequest;
 
   function extendSchema(schema) {
     var extendedSchema = schema.slice();
     extendedSchema.unshift({'type': 'string'});
     return extendedSchema;
   }
 
   function StorageNamespace(namespace, schema) {
     // Binds an API function for a namespace to its browser-side call, e.g.
-    // experimental.storage.sync.get('foo') -> (binds to) ->
-    // experimental.storage.get('sync', 'foo').
+    // storage.sync.get('foo') -> (binds to) ->
+    // storage.get('sync', 'foo').
     //
     // TODO(kalman): Put as a method on CustomBindingsObject and re-use (or
     // even generate) for other APIs that need to do this. Same for other
     // callers of registerCustomType().
     function bindApiFunction(functionName) {
       this[functionName] = function() {
         var schema = this.parameters[functionName];
         chromeHidden.validate(arguments, schema);
         return sendRequest(
-            'experimental.storage.' + functionName,
+            'storage.' + functionName,
             [namespace].concat(Array.prototype.slice.call(arguments)),
             extendSchema(schema));
       };
     }
     ['get', 'set', 'remove', 'clear'].forEach(bindApiFunction.bind(this));
   }
 
   return StorageNamespace;
 });
 
 })();