Update the analysis server diagnostic page - re-enable code completion and overlay pages,

pkg/analyzer/lib/src/dart/analysis/file_state.dart

Index: pkg/analyzer/lib/src/dart/analysis/file_state.dart
diff --git a/pkg/analyzer/lib/src/dart/analysis/file_state.dart b/pkg/analyzer/lib/src/dart/analysis/file_state.dart
index a56fe9fd9f17f3e318bf0bb82a4d4d846d0dc288..93ac117499661dc09c6ef711b5b69d8b3a9dbe08 100644
--- a/pkg/analyzer/lib/src/dart/analysis/file_state.dart
+++ b/pkg/analyzer/lib/src/dart/analysis/file_state.dart
@@ -64,6 +64,11 @@ class FileContentOverlay {
       _map[path] = content;
     }
   }
+
+  /**
+   * Return the paths currently being overridden.
+   */
+  Iterable<String> get paths => _map.keys;
 }
 
 /**