Fix most implementations of UriResolver.restoreAbsolute.

pkg/analysis_server/test/context_manager_test.dart

Index: pkg/analysis_server/test/context_manager_test.dart
diff --git a/pkg/analysis_server/test/context_manager_test.dart b/pkg/analysis_server/test/context_manager_test.dart
index 2096933c20f4bda3e4688c5d7f302f6c08cf93a3..404522860212a88caed8d30d4af849a2a70c64c2 100644
--- a/pkg/analysis_server/test/context_manager_test.dart
+++ b/pkg/analysis_server/test/context_manager_test.dart
@@ -1635,8 +1635,9 @@ class TestContextManagerCallbacks extends ContextManagerCallbacks {
     currentContextSources[path] = new HashSet<Source>();
     currentContextDispositions[path] = disposition;
     currentContext = AnalysisEngine.instance.createAnalysisContext();
-    List<UriResolver> resolvers = [new FileUriResolver()];
+    List<UriResolver> resolvers = [];
     resolvers.addAll(disposition.createPackageUriResolvers(resourceProvider));
+    resolvers.add(new FileUriResolver());
     currentContext.sourceFactory =
         new SourceFactory(resolvers, disposition.packages);
     return currentContext;