Fix for 'Create part' Quick Fix.

pkg/analysis_server/lib/src/services/correction/util.dart

Index: pkg/analysis_server/lib/src/services/correction/util.dart
diff --git a/pkg/analysis_server/lib/src/services/correction/util.dart b/pkg/analysis_server/lib/src/services/correction/util.dart
index 67ab4db734f500a80272f40807dc2ad92087d28f..9a2a8121b96761088939997cae3fb47825b826ca 100644
--- a/pkg/analysis_server/lib/src/services/correction/util.dart
+++ b/pkg/analysis_server/lib/src/services/correction/util.dart
@@ -105,7 +105,7 @@ Expression climbPropertyAccess(AstNode node) {
  * Returns the absolute (non-file) URI or `null`.
  */
 String findAbsoluteUri(AnalysisContext context, String path) {
-  Source fileSource = new NonExistingSource(path, UriKind.FILE_URI);
+  Source fileSource = new NonExistingSource(path, null, UriKind.FILE_URI);
   Uri uri = context.sourceFactory.restoreUri(fileSource);
   if (uri == null) {
     return null;