Clean up missed references to deprecated code

pkg/analyzer/lib/src/task/dart.dart

 // Copyright (c) 2015, 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.src.task.dart;
 
 import 'dart:collection';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
@@ skipping 4135 matching lines @@
         directive.uriContent = uriContent;
       }
       defaultSource = _resolveUri(isImport, uriLiteral, uriContent);
       directive.uriSource = defaultSource;
     }
 
     // Resolve all configurations and try to choose one.
     if (directive is NamespaceDirectiveImpl) {
       Source configurationSource;
       for (Configuration configuration in directive.configurations) {
-        Source source = _resolveUri(isImport, configuration.libraryUri,
-            configuration.libraryUri.stringValue);
+        Source source = _resolveUri(
+            isImport, configuration.uri, configuration.uri.stringValue);
         configuration.uriSource = source;
         if (configurationSource == null) {
           String variableName =
               configuration.name.components.map((i) => i.name).join('.');
           String variableValue = context.declaredVariables.get(variableName);
           if (configuration.value != null &&
                   variableValue == configuration.value.stringValue ||
               variableValue == 'true') {
             configurationSource = source;
           }
@@ skipping 2060 matching lines @@
   }
 
   /**
    * Check the given [directive] to see if the referenced source exists and
    * report an error if it does not.
    */
   void validateReferencedSource(UriBasedDirective directive) {
     if (directive is NamespaceDirective) {
       for (Configuration configuration in directive.configurations) {
         Source source = configuration.uriSource;
-        StringLiteral uriLiteral = configuration.libraryUri;
+        StringLiteral uriLiteral = configuration.uri;
         String uriContent = uriLiteral?.stringValue?.trim();
         if (source != null) {
           int modificationTime = sourceTimeMap[source] ?? -1;
           if (modificationTime >= 0) {
             continue;
           }
         } else {
           // Don't report errors already reported by ParseDartTask.resolveDirective
           if (UriBasedDirectiveImpl.validateUri(
                   directive is ImportDirective, uriLiteral, uriContent) !=
@@ skipping 192 matching lines @@
 
   @override
   bool moveNext() {
     if (_newSources.isEmpty) {
       return false;
     }
     currentTarget = _newSources.removeLast();
     return true;
   }
 }