Add LibraryDependencyMirror.isDeferred.

sdk/lib/mirrors/mirrors.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.
 
 // For the purposes of the mirrors library, we adopt a naming
 // convention with respect to getters and setters.  Specifically, for
 // some variable or field...
 //
 //   var myField;
 //
@@ skipping 586 matching lines @@
 }
 
 /// A mirror on an import or export declaration.
 abstract class LibraryDependencyMirror implements Mirror {
   /// Is `true` if this dependency is an import.
   bool get isImport;
 
   /// Is `true` if this dependency is an export.
   bool get isExport;
 
+  /// Returns true iff this dependency is a deferred import. Otherwise returns
+  /// false.
+  bool get isDeferred;
+
   /// Returns the library mirror of the library that imports or exports the
   /// [targetLibrary].
   LibraryMirror get sourceLibrary;
 
   /// Returns the library mirror of the library that is imported or exported.
   LibraryMirror get targetLibrary;
 
   /// Returns the prefix if this is a prefixed import and `null` otherwise.
   Symbol get prefix;
 
@@ skipping 635 matching lines @@
    *
    * When used as metadata on an import of "dart:mirrors", this metadata does
    * not apply to the library in which the annotation is used, but instead
    * applies to the other libraries (all libraries if "*" is used).
    */
   final override;
 
   const MirrorsUsed(
       {this.symbols, this.targets, this.metaTargets, this.override});
 }