Merge the dart:uri library into dart:core and update the Uri class

sdk/lib/_internal/compiler/implementation/source_file_provider.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 source_file_provider;
 
 import 'dart:async';
-import 'dart:uri';
 import 'dart:io';
 import 'dart:utf';
 
 import '../compiler.dart' as api show Diagnostic;
 import 'dart2js.dart' show AbortLeg;
 import 'colors.dart' as colors;
 import 'source_file.dart';
 import 'filenames.dart';
 import 'util/uri_extras.dart';
 
@@ skipping 99 matching lines @@
     if (fatal && throwOnError) {
       isAborting = true;
       throw new AbortLeg(message);
     }
   }
 
   void call(Uri uri, int begin, int end, String message, api.Diagnostic kind) {
     return diagnosticHandler(uri, begin, end, message, kind);
   }
 }