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

samples/ui_lib/view/view.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("view");
 
 #import('dart:html');
+#import('dart:math', prefix: 'Math');
+
 #import('../base/base.dart');
 #import('../observable/observable.dart');
 #import('../touch/touch.dart');
 #import('../layout/layout.dart');
 
 #source('CompositeView.dart');
 #source('ConveyorView.dart');
 #source('MeasureText.dart');
 #source('PagedViews.dart');
 #source('SliderMenu.dart');
@@ skipping 344 matching lines @@
     }
   }
 
   void _applyLayout() {
     if (_layout != null) {
       _layout.applyLayout();
     }
     _applyLayoutToChildren();
   }
 }