Use relative URIs for core library part-of statements.

sdk/lib/math/random.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.
 
-part of dart.math;
+part of "math.dart";
 
 /**
  * A generator of random bool, int, or double values.
  *
  * The default implementation supplies a stream of
  * pseudo-random bits that are not suitable for cryptographic purposes.
  *
  * Use the Random.secure() constructor for cryptographic
  * purposes.
  */
@@ skipping 28 matching lines @@
    * Generates a non-negative random floating point value uniformly distributed
    * in the range from 0.0, inclusive, to 1.0, exclusive.
    */
   double nextDouble();
 
   /**
    * Generates a random boolean value.
    */
   bool nextBool();
 }