Clean up mime package.

pkg/mime/lib/src/default_extension_map.dart

 // Copyright (c) 2013, 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.
 
 library mime.extension_map;
 
-// TODO(ajohnsen): Use sorted list and binary search?
-const Map<String, String> DEFAULT_EXTENSION_MAP = const <String, String>{
+// TODO(ajohnsen): Use const map once Issue 7559 is fixed.
+final Map<String, String> defaultExtensionMap = <String, String>{
 '123':'application/vnd.lotus-1-2-3',
 '3dml':'text/vnd.in3d.3dml',
 '3ds':'image/x-3ds',
 '3g2':'video/3gpp2',
 '3gp':'video/3gpp',
 '7z':'application/x-7z-compressed',
 'aab':'application/x-authorware-bin',
 'aac':'audio/x-aac',
 'aam':'application/x-authorware-map',
 'aas':'application/x-authorware-seg',
@@ skipping 962 matching lines @@
 'z5':'application/x-zmachine',
 'z6':'application/x-zmachine',
 'z7':'application/x-zmachine',
 'z8':'application/x-zmachine',
 'zaz':'application/vnd.zzazz.deck+xml',
 'zip':'application/zip',
 'zir':'application/vnd.zul',
 'zirz':'application/vnd.zul',
 'zmm':'application/vnd.handheld-entertainment+xml',
 };