Don't do folder existence checks when parsing pub list results.

pkg/analyzer/test/source/package_map_provider_test.dart

Index: pkg/analyzer/test/source/package_map_provider_test.dart
diff --git a/pkg/analyzer/test/source/package_map_provider_test.dart b/pkg/analyzer/test/source/package_map_provider_test.dart
index 311a5f57c19a3f2add68caa911e43b00e8476c02..d2d890badb70c7d75577f291f5a72bda14141fc0 100644
--- a/pkg/analyzer/test/source/package_map_provider_test.dart
+++ b/pkg/analyzer/test/source/package_map_provider_test.dart
@@ -52,7 +52,7 @@ main() {
         expect(result[packageName][0].path, equals(folderPath));
       });
 
-      test('ignore nonexistent folder', () {
+      test("don't ignore nonexistent folder", () {
         String packageName = 'foo';
         String folderPath = '/path/to/folder';
         Map<String, List<Folder>> result = parsePackageMap({
@@ -60,7 +60,11 @@ main() {
             packageName: folderPath
           }
         }).packageMap;
-        expect(result, hasLength(0));
+        expect(result, hasLength(1));
+        expect(result.keys, contains(packageName));
+        expect(result[packageName], hasLength(1));
+        expect(result[packageName][0], new isInstanceOf<Folder>());
+        expect(result[packageName][0].path, equals(folderPath));
       });
 
       test('package maps to list', () {