Deprecate Math object in corelib in favor of dart:math library.

samples/chat/chat_server_lib.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.
 
 #library("chat_server");
 #import("dart:io");
 #import("dart:isolate");
 #import("dart:json");
+#import("dart:math");
 
 void startChatServer() {
   var server = new ChatServer();
   server.init();
   port.receive(server.dispatch);
 }
 
 class ChatServer extends IsolatedServer {
 }
 
@@ skipping 31 matching lines @@
   }
 
   ReceivePort _statusPort;  // Port for receiving messages from the server.
   SendPort _serverPort;  // Port for sending messages to the server.
 }
 
 
 class User {
   User(this._handle) {
     // TODO(sgjesse) Generate more secure and unique session id's.
-    _sessionId = "a${(Math.random() * 1000000).toInt()}";
+    var rand = new Random();
+    _sessionId = "a${rand.nextInt(1000000)}";
     markActivity();
   }
 
   void markActivity() { _lastActive = new Date.now(); }
   Duration idleTime(Date now) => now.difference(_lastActive);
 
   String get handle() => _handle;
   String get sessionId() => _sessionId;
 
   String _handle;
@@ skipping 611 matching lines @@
     }
   }
 
   int _timeRange;
   List<int> _buckets;
   int _currentBucket;
   int _currentBucketTime;
   num _bucketTimeRange;
   int _sum;
 }