Implement WebStorageArea::containsItem(key) in chrome and drt/test_shell.

webkit/dom_storage/dom_storage_cached_area.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 WEBKIT_DOM_STORAGE_DOM_STORAGE_CACHED_AREA_H_
 #define WEBKIT_DOM_STORAGE_DOM_STORAGE_CACHED_AREA_H_
 #pragma once
 
 #include <map>
 
@@ skipping 17 matching lines @@
  public:
   DomStorageCachedArea(int64 namespace_id, const GURL& origin,
                        DomStorageProxy* proxy);
 
   int64 namespace_id() const { return namespace_id_; }
   const GURL& origin() const { return origin_; }
 
   unsigned GetLength(int connection_id);
   NullableString16 GetKey(int connection_id, unsigned index);
   NullableString16 GetItem(int connection_id, const string16& key);
+  bool ContainsItem(int connection_id, const string16& key);
   bool SetItem(int connection_id, const string16& key, const string16& value,
                const GURL& page_url);
   void RemoveItem(int connection_id, const string16& key,
                   const GURL& page_url);
   void Clear(int connection_id, const GURL& page_url);
 
   void ApplyMutation(const NullableString16& key,
                      const NullableString16& new_value);
 
  private:
@@ skipping 30 matching lines @@
   int64 namespace_id_;
   GURL origin_;
   scoped_refptr<DomStorageMap> map_;
   scoped_refptr<DomStorageProxy> proxy_;
   base::WeakPtrFactory<DomStorageCachedArea> weak_factory_;
 };
 
 }  // namespace dom_storage
 
 #endif  // WEBKIT_DOM_STORAGE_DOM_STORAGE_CACHED_AREA_H_