ServiceWorker, remove old Cache API implementation to make way for the polyfill.

Source/modules/serviceworkers/Cache.h

-// 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.
-
-#ifndef Cache_h
-#define Cache_h
-
-#include "bindings/v8/ScriptState.h"
-#include "bindings/v8/ScriptWrappable.h"
-#include "wtf/Forward.h"
-#include "wtf/PassRefPtr.h"
-#include "wtf/RefCounted.h"
-#include "wtf/Vector.h"
-
-namespace WebCore {
-
-class ExecutionContext;
-class ScriptPromise;
-
-class Cache FINAL : public RefCounted<Cache>, public ScriptWrappable {
-public:
-    static PassRefPtr<Cache> create(const Vector<String>& urlStrings);
-    ~Cache();
-
-    ScriptPromise match(ScriptState*, const String& urlString);
-    ScriptPromise ready(ScriptState*);
-
-private:
-    Cache();
-};
-
-} // namespace WebCore
-
-#endif // Cache_h