Remove trailing commas from Blink IDLs

Source/core/html/track/TextTrack.idl

 /*
  * 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
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 [
     EnabledAtRuntime=videoTrack,
-    EventTarget,
+    EventTarget
 ] interface TextTrack {
     readonly attribute DOMString kind;
     readonly attribute DOMString label;
     readonly attribute DOMString language;
 
     attribute DOMString mode;
 
     readonly attribute TextTrackCueList cues;
     readonly attribute TextTrackCueList activeCues;
              attribute EventListener oncuechange;
 
     void addCue(TextTrackCue cue);
     [RaisesException] void removeCue(TextTrackCue cue);
 
 #if defined(ENABLE_WEBVTT_REGIONS) && ENABLE_WEBVTT_REGIONS
     readonly attribute TextTrackRegionList regions;
     void addRegion(TextTrackRegion region);
     [RaisesException] void removeRegion(TextTrackRegion region);
 #endif
 
     // EventTarget interface
     void addEventListener(DOMString type,
                           EventListener listener,
                           optional boolean useCapture);
     void removeEventListener(DOMString type,
                              EventListener listener,
                              optional boolean useCapture);
     [RaisesException] boolean dispatchEvent(Event evt);
 };