Adds a repeatable --url_mapping flag to dartanalyzer

pkg/analyzer/lib/src/analyzer_impl.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 analyzer_impl;
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:io';
 
@@ skipping 121 matching lines @@
    * then both will be printed. If [printMode] is `2`, then only performance
    * information will be printed, and it will be marked as being for a cold VM.
    */
   ErrorSeverity analyzeSync({int printMode: 1}) {
     setupForAnalysis();
     return _analyzeSync(printMode);
   }
 
   void prepareAnalysisContext(JavaFile sourceFile, Source source) {
     List<UriResolver> resolvers = [
+        new CustomUriResolver(options.customUrlMappings),
         new DartUriResolver(sdk),
         new FileUriResolver()];
     // may be add package resolver
     {
       JavaFile packageDirectory;
       if (options.packageRootPath != null) {
         packageDirectory = new JavaFile(options.packageRootPath);
         resolvers.add(new PackageUriResolver([packageDirectory]));
       } else {
         PubPackageMapProvider pubPackageMapProvider =
@@ skipping 287 matching lines @@
     }
   }
 
   @override
   void logInformation2(String message, Object exception) {
     if (log) {
       stdout.writeln(message);
     }
   }
 }