Remove explicit interface versions of dartdoc files.

lib/html/doc/interface/WebGLDebugRendererInfo.dartdoc

Index: lib/html/doc/interface/WebGLDebugRendererInfo.dartdoc
diff --git a/lib/html/doc/interface/WebGLDebugRendererInfo.dartdoc b/lib/html/doc/interface/WebGLDebugRendererInfo.dartdoc
deleted file mode 100644
index 8aa1a5a6781125e9112d67d79ae2a2cd0b0a17d3..0000000000000000000000000000000000000000
--- a/lib/html/doc/interface/WebGLDebugRendererInfo.dartdoc
+++ /dev/null
@@ -1,15 +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 WebGLDebugRendererInfo
-interface WebGLDebugRendererInfo {
-
-  static final int UNMASKED_RENDERER_WEBGL = 0x9246;
-
-  static final int UNMASKED_VENDOR_WEBGL = 0x9245;
-}