Initial ServiceWorker CacheStorage API polyfill.

Source/modules/serviceworkers/polyfills/cachePolyfill.js

 // 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.
 
 // A simple, incomplete implementation of the Cache API, intended to facilitate
 // end to end serviceworker testing.
 
-// See https://slightlyoff.github.io/ServiceWorker/spec/service_worker/index.html#cache
+// See https://slightlyoff.github.io/ServiceWorker/spec/service_worker/index.html#cache-objects
 
 // FIXME: Support AbstractResponse/OpaqueResponse correctly.
 // FIXME: Serialize the cache.
-// FIXME: Implement CacheStorage API.
 // FIXME: Bind all function references.
 (function(global) {
     var _castToRequest = function(item) {
         if (typeof item === 'string') {
             item = new Request({
                 url: item,
             });
         }
         return item;
     };
@@ skipping 89 matching lines @@
             var entry = entriesByUrl[request.url];
             resolve(entry);
         });
     };
 
     // FIXME: Implement this.
     Cache.prototype.matchAll = Promise.reject.bind(Promise, 'Cache.prototype.matchAll not implemented.');
 
     global.Cache = global.Cache || Cache;
 }(self));  // window or worker global scope.