Introduces the new syntax for deferred loading

sdk/lib/_internal/compiler/implementation/scanner/parser.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 scanner;
 
 class FormalParameterType {
   final String type;
   const FormalParameterType(this.type);
   bool get isRequired => this == REQUIRED;
@@ skipping 77 matching lines @@
     listener.endLibraryName(libraryKeyword, semicolon);
     return token;
   }
 
   /// import uri (as identifier)? combinator* ';'
   Token parseImport(Token token) {
     Token importKeyword = token;
     listener.beginImport(importKeyword);
     assert(optional('import', token));
     token = parseLiteralStringOrRecoverExpression(token.next);
+    Token deferredKeyword;
+    if (optional('deferred', token)) {
+      deferredKeyword = token;
+      token = token.next;
+    }
     Token asKeyword;
     if (optional('as', token)) {
       asKeyword = token;
       token = parseIdentifier(token.next);
     }
     token = parseCombinators(token);
     Token semicolon = token;
     token = expect(';', token);
-    listener.endImport(importKeyword, asKeyword, semicolon);
+    listener.endImport(importKeyword, deferredKeyword, asKeyword, semicolon);
     return token;
   }
 
   /// export uri combinator* ';'
   Token parseExport(Token token) {
     Token exportKeyword = token;
     listener.beginExport(exportKeyword);
     assert(optional('export', token));
     token = parseLiteralStringOrRecoverExpression(token.next);
     token = parseCombinators(token);
@@ skipping 2316 matching lines @@
     }
     listener.handleContinueStatement(hasTarget, continueKeyword, token);
     return expectSemicolon(token);
   }
 
   Token parseEmptyStatement(Token token) {
     listener.handleEmptyStatement(token);
     return expectSemicolon(token);
   }
 }