Remove explicit interface versions of dartdoc files.

lib/html/doc/interface/CSSImportRule.dartdoc

Index: lib/html/doc/interface/CSSImportRule.dartdoc
diff --git a/lib/html/doc/interface/CSSImportRule.dartdoc b/lib/html/doc/interface/CSSImportRule.dartdoc
deleted file mode 100644
index e1b7be1ebfcd204415585359ab7b9bc8c85cd1f4..0000000000000000000000000000000000000000
--- a/lib/html/doc/interface/CSSImportRule.dartdoc
+++ /dev/null
@@ -1,20 +0,0 @@
-// 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 CSSImportRule
-interface CSSImportRule extends CSSRule {
-
-  /** @domName CSSImportRule.href */
-  final String href;
-
-  /** @domName CSSImportRule.media */
-  final MediaList media;
-
-  /** @domName CSSImportRule.styleSheet */
-  final CSSStyleSheet styleSheet;
-}