Remove explicit interface versions of dartdoc files.

lib/html/doc/interface/SVGMatrix.dartdoc

-// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-// WARNING:
-//   This file contains documentation that is merged into the real source.
-//   Do not make code changes here.
-
-/// @domName SVGMatrix
-interface SVGMatrix {
-
-  /** @domName SVGMatrix.a */
-  num a;
-
-  /** @domName SVGMatrix.b */
-  num b;
-
-  /** @domName SVGMatrix.c */
-  num c;
-
-  /** @domName SVGMatrix.d */
-  num d;
-
-  /** @domName SVGMatrix.e */
-  num e;
-
-  /** @domName SVGMatrix.f */
-  num f;
-
-  /** @domName SVGMatrix.flipX */
-  SVGMatrix flipX();
-
-  /** @domName SVGMatrix.flipY */
-  SVGMatrix flipY();
-
-  /** @domName SVGMatrix.inverse */
-  SVGMatrix inverse();
-
-  /** @domName SVGMatrix.multiply */
-  SVGMatrix multiply(SVGMatrix secondMatrix);
-
-  /** @domName SVGMatrix.rotate */
-  SVGMatrix rotate(num angle);
-
-  /** @domName SVGMatrix.rotateFromVector */
-  SVGMatrix rotateFromVector(num x, num y);
-
-  /** @domName SVGMatrix.scale */
-  SVGMatrix scale(num scaleFactor);
-
-  /** @domName SVGMatrix.scaleNonUniform */
-  SVGMatrix scaleNonUniform(num scaleFactorX, num scaleFactorY);
-
-  /** @domName SVGMatrix.skewX */
-  SVGMatrix skewX(num angle);
-
-  /** @domName SVGMatrix.skewY */
-  SVGMatrix skewY(num angle);
-
-  /** @domName SVGMatrix.translate */
-  SVGMatrix translate(num x, num y);
-}