Remove generated directories with 100s of files.

client/html/generated/html/dartium/DirectoryReader.dart

Index: client/html/generated/html/dartium/DirectoryReader.dart
diff --git a/client/html/generated/html/dartium/DirectoryReader.dart b/client/html/generated/html/dartium/DirectoryReader.dart
deleted file mode 100644
index 250c06789362bd7d97722d3a4c77e37c0459e6b0..0000000000000000000000000000000000000000
--- a/client/html/generated/html/dartium/DirectoryReader.dart
+++ /dev/null
@@ -1,14 +0,0 @@
-
-class _DirectoryReaderImpl extends _DOMTypeBase implements DirectoryReader {
-  _DirectoryReaderImpl._wrap(ptr) : super._wrap(ptr);
-
-  void readEntries(EntriesCallback successCallback, [ErrorCallback errorCallback = null]) {
-    if (errorCallback === null) {
-      _ptr.readEntries(_unwrap(successCallback));
-      return;
-    } else {
-      _ptr.readEntries(_unwrap(successCallback), _unwrap(errorCallback));
-      return;
-    }
-  }
-}