Have bindings layer assume and insist that all interface types are GCed.

third_party/WebKit/Source/core/svg/SVGMatrix.idl

 /*
  * Copyright (C) 2004, 2005 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005 Rob Buis <buis@kde.org>
  * Copyright (C) 2006 Samuel Weinig <sam.weinig@gmail.com>
  * Copyright (C) 2006 Apple Inc. All rights reserved.
  *
  * 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.
  */
 
 // http://www.w3.org/TR/SVG11/coords.html#InterfaceSVGMatrix
 
 // TODO(philipj): SVGMatrix is gone from SVG 2, replaced by DOMMatrix.
 [
     ImplementedAs=SVGMatrixTearOff,
     SetWrapperReferenceTo(SVGTransform contextTransform),
-    GarbageCollected,
 ] interface SVGMatrix {
     // FIXME: these attributes should all be floats but since we implement
     // AffineTransform with doubles setting these as doubles makes more sense.
     [RaisesException=Setter] attribute unrestricted double a;
     [RaisesException=Setter] attribute unrestricted double b;
     [RaisesException=Setter] attribute unrestricted double c;
     [RaisesException=Setter] attribute unrestricted double d;
     [RaisesException=Setter] attribute unrestricted double e;
     [RaisesException=Setter] attribute unrestricted double f;
 
     SVGMatrix multiply(SVGMatrix secondMatrix);
     [RaisesException] SVGMatrix inverse();
     SVGMatrix translate(unrestricted float x, unrestricted float y);
     SVGMatrix scale(unrestricted float scaleFactor);
     SVGMatrix scaleNonUniform(unrestricted float scaleFactorX, unrestricted float scaleFactorY);
     SVGMatrix rotate(unrestricted float angle);
     [RaisesException] SVGMatrix rotateFromVector(unrestricted float x, unrestricted float y);
     SVGMatrix flipX();
     SVGMatrix flipY();
     SVGMatrix skewX(unrestricted float angle);
     SVGMatrix skewY(unrestricted float angle);
 };