Revert of [ServiceWorker] Make Response class better conformance with the spec.

Source/modules/serviceworkers/HeaderMap.idl

Index: Source/modules/serviceworkers/HeaderMap.idl
diff --git a/Source/modules/serviceworkers/HeaderMap.idl b/Source/modules/serviceworkers/HeaderMap.idl
new file mode 100644
index 0000000000000000000000000000000000000000..38d198bda48eda69952f48a42f53e83ef8f72fd0
--- /dev/null
+++ b/Source/modules/serviceworkers/HeaderMap.idl
@@ -0,0 +1,28 @@
+// 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.
+
+// http://fetch.spec.whatwg.org/#headers-class
+// FIXME: Fetch spec has renamed this to just 'Headers'
+// FIXME: This should be defined as MapClass(DOMString, DOMString)
+// once binding code supports it (http://crbug.com/347435).
+[
+    Constructor,
+    RuntimeEnabled=ServiceWorker,
+    Exposed=ServiceWorker
+] interface HeaderMap {
+    readonly attribute unsigned long size;
+
+    // FIXME: Define keys, values, entries.
+    // FIXME: Some of the method definitions (like set) don't strictly
+    // follow the MapClass's ones (http://heycam.github.io/webidl/#MapClass),
+    // as this is supposed to be a transient implementation until we have real
+    // MapClass.
+
+    void clear();
+    [ImplementedAs=remove] boolean delete(DOMString key);
+    DOMString get(DOMString key);
+    boolean has(DOMString key);
+    void set(DOMString key, DOMString value);
+    void forEach(HeaderMapForEachCallback callback, optional any thisArg);
+};