Change Maps to HashMaps to save in performance, index and generated directories not touched

pkg/analysis_server/lib/src/resource.dart

Index: pkg/analysis_server/lib/src/resource.dart
diff --git a/pkg/analysis_server/lib/src/resource.dart b/pkg/analysis_server/lib/src/resource.dart
index 8484cb71ff303bb0460237e6517f1b95f3b17f9a..f5e5b7bd6b894efef893b747561717bbbb5aaa61 100644
--- a/pkg/analysis_server/lib/src/resource.dart
+++ b/pkg/analysis_server/lib/src/resource.dart
@@ -282,11 +282,11 @@ class _MemoryFolder extends _MemoryResource implements Folder {
  * Use `/` as a path separator.
  */
 class MemoryResourceProvider implements ResourceProvider {
-  final Map<String, _MemoryResource> _pathToResource =
+  final HashMap<String, _MemoryResource> _pathToResource =
       new HashMap<String, _MemoryResource>();
-  final Map<String, String> _pathToContent = new HashMap<String, String>();
-  final Map<String, int> _pathToTimestamp = new HashMap<String, int>();
-  final Map<String, List<StreamController<WatchEvent>>> _pathToWatchers =
+  final HashMap<String, String> _pathToContent = new HashMap<String, String>();
+  final HashMap<String, int> _pathToTimestamp = new HashMap<String, int>();
+  final HashMap<String, List<StreamController<WatchEvent>>> _pathToWatchers =
       new HashMap<String, List<StreamController<WatchEvent>>>();
   int nextStamp = 0;