Fix for resolveRelativeUri() when the containedUri is absolute.

pkg/analyzer/lib/src/generated/utilities_dart.dart

Index: pkg/analyzer/lib/src/generated/utilities_dart.dart
diff --git a/pkg/analyzer/lib/src/generated/utilities_dart.dart b/pkg/analyzer/lib/src/generated/utilities_dart.dart
index 63c6a15cd2977fdfef6c1de7986c252dd2780a3b..2e4abf1286c29be5b3153897a44ca9dc3d7256cf 100644
--- a/pkg/analyzer/lib/src/generated/utilities_dart.dart
+++ b/pkg/analyzer/lib/src/generated/utilities_dart.dart
@@ -21,6 +21,9 @@ import 'package:analyzer/src/generated/source.dart';
  *     resolveRelativeUri(package:a/b.dart, ../c.dart) -> package:a/c.dart
  */
 Uri resolveRelativeUri(Uri baseUri, Uri containedUri) {
+  if (containedUri.isAbsolute) {
+    return containedUri;
+  }
   Uri origBaseUri = baseUri;
   try {
     bool isOpaque = baseUri.isAbsolute && !baseUri.path.startsWith('/');