Expose Cache Storage API in global window/worker scope

Source/modules/serviceworkers/GlobalCacheStorage.h

Index: Source/modules/serviceworkers/GlobalCacheStorage.h
diff --git a/Source/modules/serviceworkers/GlobalCacheStorage.h b/Source/modules/serviceworkers/GlobalCacheStorage.h
new file mode 100644
index 0000000000000000000000000000000000000000..da91768432dc2b628e71321c85fd3c7b9310814b
--- /dev/null
+++ b/Source/modules/serviceworkers/GlobalCacheStorage.h
@@ -0,0 +1,24 @@
+// Copyright 2015 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 GlobalCacheStorage_h
+#define GlobalCacheStorage_h
+
+namespace blink {
+
+class CacheStorage;
+class DOMWindow;
+class ExceptionState;
+class ScriptState;
+class WorkerGlobalScope;
+
+class GlobalCacheStorage {
+public:
+    static CacheStorage* caches(ScriptState*, DOMWindow&, ExceptionState&);
+    static CacheStorage* caches(ScriptState*, WorkerGlobalScope&, ExceptionState&);
+};
+
+} // namespace blink
+
+#endif // GlobalCacheStorage_h