Make the CSS interface members static

Source/core/frame/Window.idl

 /*
  * Copyright (C) 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 77 matching lines @@
     // HTML obsolete features
     // https://html.spec.whatwg.org/#Window-partial
     [MeasureAs=WindowCaptureEvents] void captureEvents();
     [MeasureAs=WindowReleaseEvents] void releaseEvents();
 
     // CSS Object Model (CSSOM)
     // http://dev.w3.org/csswg/cssom/#extensions-to-the-window-interface
     // FIXME: The optional pseudoElt argument should have no default.
     [NewObject, TypeChecking=Interface] CSSStyleDeclaration getComputedStyle(Element elt, optional DOMString? pseudoElt = null);
 
-    // CSS Conditional Rules Module
-    // http://dev.w3.org/csswg/css-conditional/#the-css-interface
-    // FIXME: CSS should be an interface with static members, in which
-    // case this getter would not be needed. crbug.com/496369
-    [Replaceable] readonly attribute CSS CSS;
-
     // CSSOM View Module
     // http://dev.w3.org/csswg/cssom-view/#extensions-to-the-window-interface
     [NewObject] MediaQueryList matchMedia(DOMString query);
     [SameObject, Replaceable] readonly attribute Screen screen;
 
     // browsing context
     // FIXME: The x and y arguments should not be optional. crbug.com/453421
     void moveTo(optional long x, optional long y);
     void moveBy(optional long x, optional long y);
     void resizeTo(optional long x, optional long y);
@@ skipping 93 matching lines @@
 // FIXME: make this typedef accurate once enough of http://crbug.com/240176
 // is in place.
 // FIXME: consider putting this typedef in an .idl file containing spec-wide
 // utility type definitions.
 typedef MessagePort Transferable;
 
 Window implements GlobalEventHandlers;
 Window implements WindowBase64;
 Window implements WindowEventHandlers;
 Window implements WindowTimers;