dart2js: add --preserve-uris flag.

sdk/lib/_internal/compiler/implementation/compiler.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 dart2js;
 
 /**
  * If true, print a warning for each method that was resolved, but not
  * compiled.
  */
@@ skipping 627 matching lines @@
    * Dependencies that are only included due to mirrors.
    *
    * We should get rid of this and ensure that all dependencies are
    * associated with a particular element.
    */
   // TODO(johnniwinther): This should not be a [ResolutionRegistry].
   final Registry mirrorDependencies =
       new ResolutionRegistry.internal(null, new TreeElementMapping(null));
 
   final bool enableMinification;
+
+  /// When `true` emits URIs in the reflection metadata.
+  final bool preserveUris;
+
   final bool enableTypeAssertions;
   final bool enableUserAssertions;
   final bool trustTypeAnnotations;
   final bool enableConcreteTypeInference;
   final bool disableTypeInferenceFlag;
   final bool dumpInfo;
   final bool useContentSecurityPolicy;
 
   /**
    * The maximum size of a concrete type before it widens to dynamic during
@@ skipping 269 matching lines @@
   /// Set by the backend if real reflection is detected in use of dart:mirrors.
   bool disableTypeInferenceForMirrors = false;
 
   Compiler({this.enableTypeAssertions: false,
             this.enableUserAssertions: false,
             this.trustTypeAnnotations: false,
             this.enableConcreteTypeInference: false,
             bool disableTypeInferenceFlag: false,
             this.maxConcreteTypeSize: 5,
             this.enableMinification: false,
+            this.preserveUris: false,
             this.enableNativeLiveTypeAnalysis: false,
             bool emitJavaScript: true,
             bool dart2dartMultiFile: false,
             bool generateSourceMap: true,
             bool analyzeAllFlag: false,
             bool analyzeOnly: false,
             this.analyzeMain: false,
             bool analyzeSignaturesOnly: false,
             this.preserveComments: false,
             this.verbose: false,
@@ skipping 1211 matching lines @@
   int warnings = 0;
   int hints = 0;
 }
 
 class GenericTask extends CompilerTask {
   final String name;
 
   GenericTask(this.name, Compiler compiler)
       : super(compiler);
 }