Remove trailing commas from Blink IDLs

Source/core/html/HTMLDocument.idl

 /*
  * Copyright (C) 2006, 2007, 2008 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,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  */
 
 [
-    CustomToV8,
+    CustomToV8
 ] interface HTMLDocument : Document {
     [Custom] void open();
     void close();
     [Custom, PerWorldBindings, ActivityLog=AccessForIsolatedWorlds] void write([Default=Undefined] optional DOMString text);
     [Custom, PerWorldBindings, ActivityLog=AccessForIsolatedWorlds] void writeln([Default=Undefined] optional DOMString text);
 
     readonly attribute HTMLCollection embeds;
     readonly attribute HTMLCollection plugins;
     readonly attribute HTMLCollection scripts;
 
@@ skipping 13 matching lines @@
     boolean hasFocus();
 
     // Deprecated attributes
              [TreatNullAs=NullString] attribute DOMString bgColor;
              [TreatNullAs=NullString] attribute DOMString fgColor;
              [TreatNullAs=NullString] attribute DOMString alinkColor;
              [TreatNullAs=NullString] attribute DOMString linkColor;
              [TreatNullAs=NullString] attribute DOMString vlinkColor;
 };