Remove explicit interface versions of dartdoc files.

lib/html/doc/interface/SVGTextContentElement.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 SVGTextContentElement
-interface SVGTextContentElement extends SVGElement, SVGTests, SVGLangSpace, SVGExternalResourcesRequired, SVGStylable {
-
-  static final int LENGTHADJUST_SPACING = 1;
-
-  static final int LENGTHADJUST_SPACINGANDGLYPHS = 2;
-
-  static final int LENGTHADJUST_UNKNOWN = 0;
-
-  /** @domName SVGTextContentElement.lengthAdjust */
-  final SVGAnimatedEnumeration lengthAdjust;
-
-  /** @domName SVGTextContentElement.textLength */
-  final SVGAnimatedLength textLength;
-
-  /** @domName SVGTextContentElement.getCharNumAtPosition */
-  int getCharNumAtPosition(SVGPoint point);
-
-  /** @domName SVGTextContentElement.getComputedTextLength */
-  num getComputedTextLength();
-
-  /** @domName SVGTextContentElement.getEndPositionOfChar */
-  SVGPoint getEndPositionOfChar(int offset);
-
-  /** @domName SVGTextContentElement.getExtentOfChar */
-  SVGRect getExtentOfChar(int offset);
-
-  /** @domName SVGTextContentElement.getNumberOfChars */
-  int getNumberOfChars();
-
-  /** @domName SVGTextContentElement.getRotationOfChar */
-  num getRotationOfChar(int offset);
-
-  /** @domName SVGTextContentElement.getStartPositionOfChar */
-  SVGPoint getStartPositionOfChar(int offset);
-
-  /** @domName SVGTextContentElement.getSubStringLength */
-  num getSubStringLength(int offset, int length);
-
-  /** @domName SVGTextContentElement.selectSubString */
-  void selectSubString(int offset, int length);
-}