[ServiceWorker] Implement Headers class.

Source/modules/serviceworkers/Headers.idl

 // 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,
+    Constructor(Headers input),
+    Constructor(Dictionary input),
     RuntimeEnabled=ServiceWorker,
-    Exposed=ServiceWorker
-] interface HeaderMap {
+    Exposed=ServiceWorker,
+    RaisesException=Constructor
+] interface Headers {
+    [RaisesException] void append(ByteString name, ByteString value);
+    [ImplementedAs=remove, RaisesException] void delete(ByteString key);
+    [TreatReturnedNullStringAs=Null, RaisesException] ByteString? get(ByteString key);
+    [RaisesException] sequence<ByteString> getAll(ByteString name);
+    [RaisesException] boolean has(ByteString key);
+    [RaisesException] void set(ByteString key, ByteString value);
+
+    // The followings are not defined in the spec yet.

[falken, 2014/06/27 02:08:06]

grammar nit: "following"

[horo, 2014/06/27 04:19:10]

Done.

+    // https://www.w3.org/Bugs/Public/show_bug.cgi?id=26102
     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);
+    void forEach(HeadersForEachCallback callback, optional any thisArg);
 };