Remove unneeded _IN_SDK stuff in dartdoc.

pkg/dartdoc/bin/dartdoc.dart

 // 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.
 
 /**
  * To generate docs for a library, run this script with the path to an
  * entrypoint .dart file, like:
  *
  *     $ dart dartdoc.dart foo.dart
  *
  * This will create a "docs" directory with the docs for your libraries. To
  * create these beautiful docs, dartdoc parses your library and every library
  * it imports (recursively). From each library, it parses all classes and
  * members, finds the associated doc comments and builds crosslinked docs from
  * them.
  */
 #library('dartdoc');
 
 #import('dart:io');
 
 // TODO(rnystrom): Use "package:" URL (#4968).
 #import('../lib/dartdoc.dart');
 
-// TODO(johnniwinther): Note that [IN_SDK] gets initialized to true when this
-// file is modified by the SDK deployment script. If you change, be sure to test
-// that dartdoc still works when run from the built SDK directory.
-const bool _IN_SDK = false;
-
-// TODO(johnniwinther): Trailing slashes matter due to the use of [libPath] as
-// a base URI with [Uri.resolve].
-/// Relative path to the library in which dart2js resides.
-Path get libPath => _IN_SDK
-    ? scriptDir.append('../../../lib/dart2js/')
-    : scriptDir.append('../../../');
-
 /**
  * Run this from the `pkg/dartdoc` directory.
  */
 main() {
   final args = new Options().arguments;
 
   final dartdoc = new Dartdoc();
+
+  final libPath = scriptDir.append('../../../');
   dartdoc.dartdocPath = libPath.append('pkg/dartdoc');
 
   if (args.isEmpty()) {
     print('No arguments provided.');
     printUsage();
     return;
   }
 
   final entrypoints = <Path>[];
 
@@ skipping 127 matching lines @@
                              names.
 
  --exclude-lib=<libs>        Use this option to explicitly specify which
                              libraries to exclude from the documentation. If
                              omitted, no libraries are excluded. <libs> is
                              comma-separated list of library names.
 
  --verbose                   Print verbose information during generation.
 ''');
 }