Remove explicit interface versions of dartdoc files.

lib/html/doc/interface/SVGLocatable.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 SVGLocatable
-interface SVGLocatable {
-
-  /** @domName SVGLocatable.farthestViewportElement */
-  final SVGElement farthestViewportElement;
-
-  /** @domName SVGLocatable.nearestViewportElement */
-  final SVGElement nearestViewportElement;
-
-  /** @domName SVGLocatable.getBBox */
-  SVGRect getBBox();
-
-  /** @domName SVGLocatable.getCTM */
-  SVGMatrix getCTM();
-
-  /** @domName SVGLocatable.getScreenCTM */
-  SVGMatrix getScreenCTM();
-
-  /** @domName SVGLocatable.getTransformToElement */
-  SVGMatrix getTransformToElement(SVGElement element);
-}