Use event init dictionaries in core/{css,html}

Source/core/css/MediaQueryListEventInit.idl

Index: Source/core/css/MediaQueryListEventInit.idl
diff --git a/Source/core/css/MediaQueryListEventInit.idl b/Source/core/css/MediaQueryListEventInit.idl
new file mode 100644
index 0000000000000000000000000000000000000000..69972f53fd0ce7224045b8151a2980c78de32ac3
--- /dev/null
+++ b/Source/core/css/MediaQueryListEventInit.idl
@@ -0,0 +1,10 @@
+// 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://dev.w3.org/csswg/cssom-view/#mediaquerylistevent
+
+dictionary MediaQueryListEventInit : EventInit {
+    DOMString media = "";
+    boolean matches = false;
+};