Low risk nullable => non-nullable change

third_party/WebKit/Source/core/css/CSSStyleDeclaration.idl

 /*
  * Copyright (C) 2006, 2007, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Samuel Weinig <sam.weinig@gmail.com>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 12 matching lines @@
 [
     DependentLifetime,
     SetWrapperReferenceTo(CSSRule parentRule),
 ] interface CSSStyleDeclaration {
     [CEReactions, RaisesException=Setter] attribute DOMString cssText;
     readonly attribute unsigned long length;
     getter DOMString item(unsigned long index);
     DOMString getPropertyValue(DOMString property);
     DOMString getPropertyPriority(DOMString property);
     // TODO(foolip): The value and priority arguments should have
     // [TreatNullAs=EmptyString] and should not be nullable.

[foolip, 2016/12/14 12:07:00]

Can remove the TODO now. Tests needed.

[lunalu1, 2016/12/14 13:59:04]

Done.

-    [CEReactions, RaisesException] void setProperty(DOMString property, DOMString? value, optional DOMString? priority = null);
+    [CEReactions, RaisesException] void setProperty(DOMString property, [TreatNullAs=EmptyString] DOMString value, [TreatNullAs=EmptyString] optional DOMString priority = "");
     // void setPropertyValue(DOMString property, [TreatNullAs=EmptyString] DOMString value);
     // void setPropertyPriority(DOMString property, [TreatNullAs=EmptyString] DOMString priority);
     [CEReactions, RaisesException] DOMString removeProperty(DOMString property);
     readonly attribute CSSRule? parentRule;
     [CEReactions, RaisesException=Setter, TreatNullAs=EmptyString] attribute DOMString cssFloat;
 
     // The camel-cased and dashed attribute getters have custom bindings.
     // https://dev.w3.org/csswg/cssom/#dom-cssstyledeclaration-camel-cased-attribute
     // https://dev.w3.org/csswg/cssom/#dom-cssstyledeclaration-dashed-attribute
     [Custom=(PropertyGetter,PropertyEnumerator,PropertyQuery)] getter (DOMString or float) (DOMString name);
     [Custom] setter void (DOMString property, DOMString? propertyValue);
 };