Remove generated directories with 100s of files.

client/dom/generated/src/frog/MutationEvent.dart

Index: client/dom/generated/src/frog/MutationEvent.dart
diff --git a/client/dom/generated/src/frog/MutationEvent.dart b/client/dom/generated/src/frog/MutationEvent.dart
deleted file mode 100644
index e26cac7b31175f7cb28be2343d8f9564316c1d93..0000000000000000000000000000000000000000
--- a/client/dom/generated/src/frog/MutationEvent.dart
+++ /dev/null
@@ -1,21 +0,0 @@
-
-class _MutationEventJs extends _EventJs implements MutationEvent native "*MutationEvent" {
-
-  static final int ADDITION = 2;
-
-  static final int MODIFICATION = 1;
-
-  static final int REMOVAL = 3;
-
-  final int attrChange;
-
-  final String attrName;
-
-  final String newValue;
-
-  final String prevValue;
-
-  final _NodeJs relatedNode;
-
-  void initMutationEvent(String type, bool canBubble, bool cancelable, _NodeJs relatedNode, String prevValue, String newValue, String attrName, int attrChange) native;
-}