fix MemoryResourceProvider context on Windows

pkg/analyzer/test/src/context/source_test.dart

Index: pkg/analyzer/test/src/context/source_test.dart
diff --git a/pkg/analyzer/test/src/context/source_test.dart b/pkg/analyzer/test/src/context/source_test.dart
index dcb81ace602c95d90d7f65504c0d665cf00a9d3b..1fc0784769b00d9661442db96c8472f34f9cde03 100644
--- a/pkg/analyzer/test/src/context/source_test.dart
+++ b/pkg/analyzer/test/src/context/source_test.dart
@@ -30,10 +30,7 @@ class SourceFactoryImplTest extends AbstractContextTest {
       new _MockPackages(packageUriMap),
     );
     Uri uri = sourceFactory.restoreUri(newSource('/pkgs/somepkg/lib'));
-    // TODO(danrubel) fix on Windows
-    if (resourceProvider.absolutePathContext.separator != r'\') {
-      expect(uri, Uri.parse('package:foo/'));
-    }
+    expect(uri, Uri.parse('package:foo/'));
   }
 }